Firefox MCP Server

by JediLuke

Overview Schema Related Servers Score Discussions

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Server Quality Checklist

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Latest release: v1.0.0
Disambiguation4/5
Most tools have distinct purposes, but some overlap exists between click, send_key, and type_text for user input actions, and between get_page_content and get_page_text for content extraction. The descriptions help clarify differences, but an agent might occasionally misselect between these similar tools.
Naming Consistency5/5
Tool names follow a consistent snake_case pattern with clear verb_noun structures throughout, such as navigate, get_current_url, and create_tab. There are no deviations in naming conventions, making the set predictable and easy to parse.
Tool Count3/5
With 29 tools, the count feels heavy for a browser automation server, bordering on excessive. While the tools cover many aspects, some could potentially be consolidated or omitted without losing functionality, making the set slightly overwhelming for its scope.
Completeness5/5
The tool set provides comprehensive coverage for browser automation and debugging, including navigation, tab management, content extraction, user interactions, monitoring, and debugging features. There are no obvious gaps; agents can perform full workflows from launching the browser to analyzing performance and errors.
Average 2.5/5 across 29 of 29 tools scored. Lowest: 1.3/5.
See the Tool Scores section below for per-tool breakdowns.
- No community issues in the last 6 months
- 0 commits in the last 12 weeks
- No stable releases found
- No critical vulnerability alerts
- No high-severity vulnerability alerts
- No code scanning findings
- CI status not available
This repository is licensed under MIT License.
This repository includes a README.md file.
No tool usage detected in the last 30 days. Usage tracking helps demonstrate server value.
Tip: use the "Try in Browser" feature on the server page to seed initial usage.
Add a glama.json file to provide metadata about your server.
If you are the author, simply .
If the server belongs to an organization, first add glama.json to the root of your repository:
```
{
  "$schema": "https://glama.ai/mcp/schemas/server.json",
  "maintainers": [
    "your-github-username"
  ]
}
```
Then . Browse examples.
Add related servers to improve discoverability.

How to sync the server with GitHub?

Servers are automatically synced at least once per day, but you can also sync manually at any time to instantly update the server profile.

To manually sync the server, click the "Sync Server" button in the MCP server admin interface.

How is the quality score calculated?

The overall quality score combines two components: Tool Definition Quality (70%) and Server Coherence (30%).

Tool Definition Quality measures how well each tool describes itself to AI agents. Every tool is scored 1–5 across six dimensions: Purpose Clarity (25%), Usage Guidelines (20%), Behavioral Transparency (20%), Parameter Semantics (15%), Conciseness & Structure (10%), and Contextual Completeness (10%). The server-level definition quality score is calculated as 60% mean TDQS + 40% minimum TDQS, so a single poorly described tool pulls the score down.

Server Coherence evaluates how well the tools work together as a set, scoring four dimensions equally: Disambiguation (can agents tell tools apart?), Naming Consistency, Tool Count Appropriateness, and Completeness (are there gaps in the tool surface?).

Tiers are derived from the overall score: A (≥3.5), B (≥3.0), C (≥2.0), D (≥1.0), F (<1.0). B and above is considered passing.

Tool Scores

Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden for behavioral disclosure but offers none. It doesn't indicate whether this is a read or write operation, what visual feedback occurs, whether it requires specific page states, what errors might occur, or any performance characteristics. The agent must infer everything from the parameter names alone.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness2/5
Is the description appropriately sized, front-loaded, and free of redundancy?
While technically concise with just three words, this is under-specification rather than effective brevity. The description fails to provide any meaningful information that would help an agent understand or use the tool correctly, making it inefficient despite its short length.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness1/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a complex 8-parameter UI interaction tool with no annotations, no output schema, and rich sibling tools, the description is completely inadequate. It provides no information about what the tool does, how to use it, what parameters mean, what behavior to expect, or what results might be returned.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters1/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 8 parameters and 0% schema description coverage, the description provides zero information about what any parameter means or how they interact. Critical parameters like 'selector', 'fromCoordinates', 'toCoordinates', 'offsetX/Y', 'duration', 'steps', and 'tabId' are completely unexplained, leaving the agent to guess their purposes and relationships.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose2/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Perform drag operation' is a tautology that merely restates the tool name 'drag' without specifying what resource is being dragged or in what context. It doesn't distinguish this tool from other UI interaction siblings like 'click' or 'send_key', leaving the agent to guess what exactly gets dragged and where.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines1/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided about when to use this tool versus alternatives. With 28 sibling tools including various UI interactions like 'click', 'type_text', and 'send_key', the description offers no context about appropriate use cases, prerequisites, or when other tools might be more suitable for different interaction needs.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. 'Click on an element' implies a user interaction but reveals nothing about side effects (e.g., page navigation, state changes), error conditions (e.g., if the element is missing), performance (e.g., timing delays), or response format. This is inadequate for a tool with potential mutative effects in a browser automation context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is concise ('Click on an element') but under-specified, not efficiently informative. It uses a single sentence that is front-loaded but lacks necessary detail, making it more sparse than appropriately brief. While not verbose, it does not earn its place by adding value beyond the tool name.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness1/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the complexity of browser automation (with 3 parameters, nested objects, and no output schema) and the absence of annotations, the description is severely incomplete. It does not cover parameter usage, behavioral outcomes, error handling, or integration with sibling tools (e.g., 'navigate' or 'wait_for_element'). This leaves critical gaps for an agent to use the tool effectively.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters1/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema has 3 parameters (coordinates, selector, tabId) with 0% description coverage, meaning none are documented in the schema. The description adds no information about these parameters—it does not explain what 'coordinates' or 'selector' refer to, how they interact, or which parameter(s) are required for clicking. This fails to compensate for the schema's lack of documentation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose2/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Click on an element' is a tautology that restates the tool name 'click' with minimal elaboration. It specifies a verb ('click') but only vaguely identifies the resource ('an element') without clarifying what constitutes an element in this context (e.g., UI element, DOM element). It does not distinguish this tool from siblings like 'drag' or 'send_key', which also interact with elements.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines1/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., needing an open tab or loaded page), exclusions (e.g., when elements are not clickable), or comparisons to sibling tools like 'drag' or 'send_key'. Without any context, an agent cannot infer appropriate usage scenarios.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure but offers none. It doesn't indicate whether this is a read or write operation, what permissions might be needed, whether it's destructive (e.g., could trigger unintended actions), what happens on failure, or any rate limits. The description is completely silent on behavioral characteristics beyond the basic action implied by the name.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise at just three words, which could be appropriate if it were more informative. There's no wasted verbiage or unnecessary elaboration. However, this brevity comes at the cost of being under-specified rather than efficiently informative.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness1/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a tool with 5 parameters, 0% schema description coverage, no annotations, and no output schema, the description is completely inadequate. It doesn't explain what the tool actually does beyond the name, provides no parameter guidance, offers no behavioral context, and gives no indication of return values or error conditions. This leaves the agent with insufficient information to use the tool correctly.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters1/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 5 parameters and 0% schema description coverage, the schema provides only type information with no semantic meaning. The description adds zero information about what any parameter does - not explaining what 'key' represents (physical key codes? character strings?), what 'modifiers' are (Ctrl, Shift, etc.), what 'repeat' controls, what 'selector' targets, or what 'tabId' identifies. The description fails completely to compensate for the schema's lack of documentation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose2/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Send keyboard events' is a tautology that essentially restates the tool name 'send_key' without adding meaningful specificity. While it indicates the general domain (keyboard input), it doesn't specify what kind of events, to what target, or how they differ from sibling tools like 'type_text' or 'click'. The description lacks the verb+resource clarity needed for proper differentiation.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines1/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides absolutely no guidance on when to use this tool versus alternatives. With sibling tools like 'type_text' (for text input) and 'click' (for mouse interactions), the agent has no indication whether this is for single keys, key combinations, form submissions, or other use cases. There's no mention of prerequisites, target contexts, or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure but offers minimal information. 'Navigate back' implies a navigation action but doesn't specify what gets navigated, whether this requires specific browser state, what happens if there's no history to go back to, or what the expected outcome is. For a navigation tool with zero annotation coverage, this is inadequate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise at just two words. While it may be under-specified, it's not verbose or poorly structured - every word serves a purpose in conveying the core action.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness1/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a navigation tool with no annotations, no output schema, and a completely undocumented parameter, the description is completely inadequate. It doesn't explain what 'back' means in this context, what resource it operates on, what the parameter does, or what the expected outcome is. The description fails to provide the necessary context for an agent to use this tool effectively.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The schema has 1 parameter (tabId) with 0% description coverage, meaning the parameter is completely undocumented in the schema. The description 'Navigate back' provides no information about parameters, their purpose, or how they relate to the navigation action. The description doesn't compensate for the schema's lack of parameter documentation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose2/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Navigate back' is a tautology that essentially restates the tool name 'back' with a synonym. While it suggests navigation functionality, it doesn't specify what resource is being navigated (browser history, application state, etc.) or distinguish this from sibling navigation tools like 'forward' or 'navigate'.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines1/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance about when to use this tool versus alternatives. There are multiple navigation-related sibling tools (forward, navigate, reload, get_current_url), but the description offers no context about when 'back' is appropriate versus these other options or any prerequisites for its use.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. 'Reload page' implies a mutation (refreshing content), but it doesn't specify effects like page state changes, network requests, or potential side effects. It offers no behavioral details beyond the basic action.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise with just two words, front-loading the core action. There's no wasted text, though this brevity contributes to underspecification rather than clarity.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness1/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's mutation nature (reloading implies change), no annotations, no output schema, and 1 undocumented parameter, the description is severely incomplete. It doesn't address behavior, parameters, or outcomes, making it inadequate for effective use.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema has 1 parameter (tabId) with 0% description coverage, and the description adds no parameter information. It doesn't explain what 'tabId' is, how to obtain it, or its role in reloading, failing to compensate for the schema's lack of documentation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose2/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Reload page' restates the tool name 'reload' with minimal elaboration, making it a tautology. It doesn't specify what resource is being reloaded (e.g., a browser tab) or distinguish it from sibling tools like 'navigate' or 'back', though the context suggests it's for browser/page operations.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines1/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives like 'navigate' (for new URLs) or 'back'/'forward' (for history navigation). The description lacks any context, prerequisites, or exclusions, leaving usage unclear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must fully disclose behavioral traits. 'Set active tab' implies a mutation operation (changing the active tab), but it fails to describe critical aspects: whether this requires specific permissions, what happens to the previous active tab, if it affects browser focus, error conditions (e.g., invalid tabId), or side effects. The description is too minimal to inform safe or effective use.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise with just three words, front-loading the core action. There is no wasted language or unnecessary elaboration, making it efficient for quick scanning. However, this brevity comes at the cost of completeness, as noted in other dimensions.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness1/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (a mutation operation with no annotations, 1 undocumented parameter, and no output schema), the description is severely incomplete. It lacks essential details: purpose differentiation, usage guidelines, behavioral transparency, and parameter semantics. For a tool that likely interacts with browser state, this minimal description is inadequate for safe and effective agent use.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema has 1 parameter (tabId) with 0% description coverage, meaning the schema provides no semantic details. The description does not compensate by explaining what 'tabId' represents (e.g., a browser tab identifier, format, or how to obtain it). This leaves the parameter's meaning and usage unclear, failing to bridge the coverage gap.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose2/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Set active tab' is a tautology that merely restates the tool name without elaboration. It specifies a verb ('Set') and resource ('active tab'), but provides no details about what 'active tab' means, what browser context this applies to, or how it differs from sibling tools like 'create_tab' or 'list_tabs'. This leaves the purpose vague and indistinguishable from alternatives.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines1/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description offers no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., needing an existing tab), exclusions (e.g., not for creating new tabs), or comparisons to siblings like 'create_tab' or 'navigate'. Without any context, an agent cannot determine appropriate usage scenarios.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries full burden for behavioral disclosure. 'Navigate forward' implies a navigation action but reveals nothing about what happens (e.g., whether it's idempotent, if it waits for page load, what errors might occur, or what the return value is). This is inadequate for a tool with potential side effects.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise at two words, with zero wasted text. It's front-loaded with the core action, though this brevity comes at the cost of completeness. Every word earns its place by conveying the basic intent.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness1/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given no annotations, no output schema, and a parameter with 0% schema coverage, the description is severely incomplete. It doesn't explain what 'forward' means in context (browser history navigation), what the parameter does, what happens on execution, or what to expect as a result. This is inadequate for effective tool use.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema has 1 parameter (tabId) with 0% description coverage, and the tool description provides no information about parameters. The description doesn't mention tabId at all, leaving the agent to guess its purpose from the schema's property name alone. This fails to compensate for the schema's lack of descriptions.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose2/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Navigate forward' is a tautology that essentially restates the tool name 'forward' with a synonym. While it indicates navigation action, it doesn't specify what resource is being navigated (browser tab, page history) or distinguish it from the 'back' sibling tool that presumably handles backward navigation. The purpose is vague rather than specific.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided about when to use this tool versus alternatives. The description doesn't mention prerequisites (e.g., needing a tab with forward history available), exclusions, or relationships to sibling tools like 'back' or 'navigate'. The agent must infer usage from context alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It fails to describe how the tool behaves: whether it returns raw HTML, handles dynamic content, requires page load completion, or has any side effects (e.g., triggering page events). This is inadequate for a tool with potential complexity in web interactions.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise with just three words, front-loaded and zero waste. However, this brevity comes at the cost of under-specification, but as per scoring rules, conciseness is rated independently based on efficiency, not completeness.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's potential complexity (web scraping/interaction), lack of annotations, no output schema, and 0% schema coverage, the description is incomplete. It doesn't cover return values, error conditions, or behavioral nuances, making it insufficient for effective agent use.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The description provides no information about the two parameters ('selector' and 'tabId'), and schema description coverage is 0%, leaving both undocumented. It doesn't explain what 'selector' refers to (e.g., CSS selector for targeting elements) or 'tabId' (e.g., identifier for browser tabs), failing to compensate for the schema gap.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose3/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Get HTML content' states a clear verb ('Get') and resource ('HTML content'), but it's vague about scope and doesn't distinguish from sibling tools like 'get_page_text' or 'get_current_url'. It lacks specificity about what 'HTML content' means (e.g., full page HTML, selected element HTML, or rendered HTML).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives like 'get_page_text' (for text content) or 'get_current_url' (for URL retrieval). The description doesn't mention prerequisites (e.g., requires a loaded page or active tab) or exclusions, leaving usage context unclear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It fails to explain what 'debugging helper functions' are, whether this modifies page state permanently, what permissions are required, or what the expected outcome is. This is inadequate for a tool that likely performs page injection.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, efficient sentence with no wasted words. It's front-loaded with the core action and target, making it easy to parse quickly.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness1/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the lack of annotations, 0% schema coverage, no output schema, and the tool's likely complexity (injecting debugging helpers), the description is severely incomplete. It doesn't cover behavior, parameters, outcomes, or integration with sibling tools, leaving critical gaps for an AI agent.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters1/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, and the description provides no information about the two parameters ('includeWebSocketMonitoring' and 'tabId'). It doesn't explain what these parameters control, their formats, or their impact on the injection process.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('inject') and target ('debugging helper functions into the page'), providing a specific verb+resource combination. However, it doesn't explicitly differentiate from sibling tools like 'execute_script' or 'start_monitoring', which could have overlapping debugging purposes.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives like 'execute_script' for custom debugging code or 'start_monitoring' for automated debugging. The description lacks context about prerequisites, timing, or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the basic action without mentioning any behavioral traits such as whether it requires the element to be visible or interactable, if it triggers events, error handling, or performance implications. This is inadequate for a tool that interacts with web elements.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, clear sentence that directly states the tool's function without any unnecessary words. It is front-loaded and efficiently conveys the core action, making it easy to parse quickly. Every word earns its place by contributing to understanding the purpose.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness1/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the complexity of interacting with web elements, lack of annotations, 0% schema coverage, and no output schema, the description is severely incomplete. It fails to address critical aspects like parameter meanings, behavioral expectations, error conditions, or return values, making it inadequate for safe and effective tool invocation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters1/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, meaning none of the parameters (selector, tabId, text) are documented in the schema. The description adds no information about what these parameters mean, their expected formats, or how they interact. For example, it doesn't explain that 'selector' identifies the input field or that 'tabId' specifies the browser tab, leaving the agent to guess.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('Type text') and target ('into an input field'), making the purpose immediately understandable. It specifies the verb and resource, though it doesn't distinguish from sibling tools like 'send_key' which might have overlapping functionality. The description avoids tautology by not just repeating the tool name.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives like 'send_key' or 'execute_script' for text input. It lacks any context about prerequisites, such as needing an input field to be present or focused, or when other methods might be more appropriate. This leaves the agent with minimal usage direction.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It states this is a 'get' operation (implying read-only) and mentions 'combined feed' which suggests aggregation, but doesn't describe output format, pagination, rate limits, authentication needs, or whether it's destructive. For a tool with 3 parameters and no annotation coverage, this leaves significant behavioral gaps.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, efficient sentence with zero wasted words. It's appropriately sized for a simple tool and front-loads the core purpose. Every word earns its place, making it easy to parse quickly.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (3 parameters, no annotations, no output schema, multiple similar siblings), the description is incomplete. It doesn't explain what 'debug events' include, how parameters work, what the output looks like, or when to choose this over other debugging tools. For a tool in a crowded namespace with zero schema documentation, this provides insufficient context.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must compensate for undocumented parameters. The description mentions 'combined feed' which relates to the output, but adds no meaning about the 3 input parameters (limit, since, tabId). It doesn't explain what 'limit' controls, what 'since' refers to (timestamp?), or how 'tabId' filters events. This fails to compensate for the schema coverage gap.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose3/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Get combined feed of all debug events' clearly states the action (get) and resource (debug events), but it's vague about what constitutes 'debug events' and doesn't distinguish this tool from sibling tools like get_console_logs, get_javascript_errors, or get_network_activity. It specifies 'combined feed' and 'all' which provides some scope, but lacks precision about what types of events are included.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives like get_console_logs or get_network_activity. It mentions 'all debug events' which implies comprehensiveness, but doesn't specify contexts where this is preferred over more specific tools. No exclusions or prerequisites are mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool retrieves errors but doesn't explain what 'captured' means, whether it requires prior setup (e.g., monitoring), if it's read-only or has side effects, or details on error format/limitations. This leaves critical behavioral traits unspecified for a tool with potential dependencies.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, efficient sentence with no wasted words. It's front-loaded with the core purpose, making it easy to parse quickly, though this brevity contributes to gaps in other dimensions.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (retrieving dynamic error data with 3 parameters), lack of annotations, 0% schema coverage, and no output schema, the description is inadequate. It doesn't cover parameter meanings, behavioral context, or output expectations, leaving the agent with insufficient information for reliable use.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The schema has 0% description coverage, so parameters 'limit', 'since', and 'tabId' are undocumented in the schema. The description adds no information about these parameters—it doesn't mention filtering by time, tab, or pagination, failing to compensate for the schema's lack of documentation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose3/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Get captured JavaScript errors' clearly states the verb ('Get') and resource ('captured JavaScript errors'), making the basic purpose understandable. However, it doesn't distinguish this tool from sibling tools like 'get_console_logs' or 'get_all_debug_activity' that might also retrieve error-related information, leaving the scope ambiguous.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives like 'get_console_logs' or 'get_all_debug_activity'. It doesn't mention prerequisites, context (e.g., after 'start_monitoring'), or exclusions, leaving the agent to infer usage based on the name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries full burden. It mentions 'visible text content', hinting at behavior (e.g., excludes hidden elements), but lacks details on permissions, rate limits, error handling, or output format. For a tool with 2 parameters and no annotations, this is insufficient behavioral disclosure.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise with a single phrase 'Get visible text content', which is front-loaded and wastes no words. Every part earns its place by specifying the action and resource scope efficiently.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given 2 parameters with 0% schema coverage, no annotations, no output schema, and sibling tools like 'get_page_content', the description is incomplete. It doesn't explain parameter usage, return values, or how it differs from alternatives, making it inadequate for effective tool selection and invocation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must compensate. It adds no information about the 'selector' or 'tabId' parameters, their purposes, formats, or constraints. With 2 undocumented parameters, the description fails to provide meaningful semantic context beyond the basic action.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose3/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Get visible text content' clearly states the action (get) and resource (visible text content), but it's vague about scope and doesn't distinguish from siblings like 'get_page_content' or 'execute_script'. It specifies 'visible' text, which adds some differentiation from raw HTML content tools.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No explicit guidance on when to use this tool versus alternatives like 'get_page_content' or 'execute_script' for text extraction. The description implies it's for retrieving visible text, but doesn't specify contexts, prerequisites, or exclusions, leaving usage ambiguous.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must fully disclose behavioral traits. 'Navigate to a URL' implies a navigation action but lacks details on permissions, side effects (e.g., page loading, potential errors), or response behavior. This is inadequate for a tool with mutation implications.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise at three words, front-loaded with the core action. There's no wasted language, making it efficient and easy to parse, though this brevity contributes to gaps in other dimensions.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (navigation with potential side effects), no annotations, no output schema, and low schema coverage, the description is incomplete. It doesn't address return values, error handling, or interaction with sibling tools, failing to provide adequate context for safe use.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The description mentions 'a URL' but doesn't explain the 'tabId' parameter or provide any semantic context beyond the schema's 0% coverage. With two parameters (one required), the description fails to compensate for the lack of schema documentation, leaving key inputs unexplained.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Navigate to a URL' clearly states the verb ('Navigate') and resource ('a URL'), making the tool's purpose understandable. However, it doesn't distinguish this tool from potential alternatives like 'reload' or 'get_current_url' among the siblings, which would require more specificity for a perfect score.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives. With siblings like 'reload' (for refreshing), 'get_current_url' (for reading), and 'create_tab' (for new tabs), there's no indication of prerequisites, context, or exclusions, leaving usage ambiguous.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions 'wait' and 'appear', implying a time-based operation, but doesn't specify what happens on timeout, whether it polls or uses events, if it blocks execution, or what permissions are needed. For a tool with 3 parameters and no annotations, this is a significant gap in describing behavior beyond the basic action.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise with a single phrase 'Wait for element to appear', which is front-loaded and wastes no words. Every part earns its place by conveying the core action and target efficiently, making it easy to scan and understand at a glance.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (3 parameters, no annotations, no output schema), the description is incomplete. It doesn't cover parameter meanings, behavioral details like error handling or return values, or how it fits with siblings in a browser automation context. For a tool that likely interacts with web pages, more context is needed to be fully helpful.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must compensate for undocumented parameters. It adds no meaning beyond the schema—it doesn't explain what 'selector', 'tabId', or 'timeout' represent, their formats, or how they interact. With 3 parameters and no schema descriptions, the description fails to provide necessary semantic context, leaving parameters largely unexplained.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose3/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Wait for element to appear' states a clear action ('wait for') and target ('element'), but it's vague about what 'element' means in this context (e.g., DOM element, UI component) and doesn't distinguish from siblings like 'get_page_content' or 'execute_script'. It avoids tautology by not restating the name 'wait_for_element' exactly, but lacks specificity about the resource or environment.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing an active browser/tab), exclusions, or compare to siblings like 'get_page_content' for checking element existence. Usage is implied only by the action 'wait', but no explicit context or alternatives are stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It states the action is to 'clear' buffers, implying a destructive mutation, but doesn't specify whether this is reversible, requires specific permissions, or has side effects like resetting debug state. No additional behavioral traits like rate limits or auth needs are mentioned, leaving significant gaps.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, efficient sentence that front-loads the core action and target. There is no wasted verbiage, and it directly communicates the tool's function without unnecessary elaboration, making it highly concise and well-structured.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (a destructive operation with 2 parameters), lack of annotations, and no output schema, the description is incomplete. It doesn't cover parameter details, behavioral implications, or usage context, making it inadequate for an agent to fully understand how to invoke this tool correctly in practice.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The description mentions 'debug event buffers for a tab', which hints at the 'tabId' parameter, but doesn't explain the 'types' parameter or its enum values (console, errors, network, websocket). With 0% schema description coverage and 2 parameters, the description fails to compensate for the lack of schema details, leaving parameter meanings unclear.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('Clear') and target resource ('debug event buffers for a tab'), making the purpose immediately understandable. However, it doesn't distinguish this tool from siblings like 'get_all_debug_activity' or 'get_console_logs', which are read operations versus this clear operation.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives. For example, it doesn't mention whether this should be used before starting new debugging sessions or after analyzing logs, nor does it reference sibling tools like 'get_console_logs' for context. The description lacks any usage context or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. 'Close a specific tab' implies a destructive action, but it doesn't specify whether this requires the tab to be active, if it prompts for confirmation, what happens to unsaved data, or if there are side effects like browser closure. This leaves critical behavioral traits undocumented.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise with just four words, front-loading the core action without any fluff. Every word earns its place by directly conveying the tool's purpose, making it easy to scan and understand quickly.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the complexity of a destructive tab-closing operation, no annotations, no output schema, and minimal parameter semantics, the description is incomplete. It doesn't address prerequisites, error conditions, or what happens post-execution (e.g., does it return a status?), leaving significant gaps for safe and effective use.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema has 1 parameter with 0% description coverage, and the tool description doesn't add any semantic information about 'tabId'. It doesn't explain what a tabId is, how to obtain it (e.g., from 'list_tabs'), or its format (e.g., numeric vs. string). This fails to compensate for the schema's lack of documentation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Close a specific tab' clearly states the action (close) and resource (tab), making the purpose immediately understandable. However, it doesn't differentiate from sibling tools like 'close_browser' or 'set_active_tab', which could involve similar tab operations but with different scopes or intents.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives. For example, it doesn't clarify if this is for closing individual tabs while keeping the browser open (vs. 'close_browser'), or how it relates to 'set_active_tab' for tab management. Without such context, users must infer usage from the tool name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden for behavioral disclosure. It mentions 'isolated session' (suggesting separation from other tabs) and 'debugging' (implying monitoring capabilities), but lacks critical details: whether this requires specific permissions, what 'debugging' entails, how the session isolation works, or what the tool returns. For a creation tool with zero annotation coverage, this is insufficient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise (7 words) and front-loaded with the core action. Every word earns its place: 'Create' (verb), 'new tab' (resource), 'with isolated session and debugging' (key features). No wasted words or redundant information.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given 4 parameters with 0% schema coverage, no annotations, and no output schema, the description is incomplete. It doesn't explain parameter meanings, return values, error conditions, or behavioral nuances. While concise, it lacks the necessary detail for a tool that creates resources with debugging capabilities.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must compensate for undocumented parameters. It adds no information about any of the 4 parameters (contextId, enableMonitoring, tabId, url) - their purposes, formats, or relationships. The mention of 'debugging' loosely relates to 'enableMonitoring' but provides no semantic clarity. This fails to compensate for the schema gap.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('Create a new tab') and key features ('with isolated session and debugging'), which distinguishes it from basic tab creation. However, it doesn't explicitly differentiate from sibling tools like 'launch_firefox_multi' or 'set_active_tab' that might also involve tab management.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives like 'launch_firefox_multi' for browser launch or 'navigate' for URL loading. It mentions 'isolated session and debugging' but doesn't explain when this specific capability is needed versus simpler tab operations.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions execution but doesn't specify whether this is a read-only evaluation, if it modifies page state, requires specific permissions, has side effects like page reloads, or handles errors. This leaves critical behavioral traits unclear for a tool that interacts with a browser.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise with just four words, front-loading the core action without any fluff. Every word earns its place by directly conveying the tool's function, making it efficient and easy to parse.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the complexity of executing JavaScript in a browser, the lack of annotations, no output schema, and low schema coverage, the description is insufficient. It doesn't cover execution context, return values, error handling, or safety considerations, leaving significant gaps for an agent to use this tool effectively.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The schema description coverage is 0%, so the description must compensate for undocumented parameters. It mentions 'JavaScript' and 'browser', which loosely relate to the 'script' and 'tabId' parameters, but provides no details on script format, tabId usage, or whether tabId is optional. This adds minimal semantic value beyond the schema's basic structure.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the verb ('Execute') and resource ('JavaScript in the browser'), making the purpose immediately understandable. However, it doesn't distinguish this tool from potential alternatives like 'inject_debugging_helpers' or clarify if this is for evaluation vs. injection, which prevents a perfect score.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives like 'inject_debugging_helpers' or 'get_javascript_errors', nor does it mention prerequisites such as needing an active browser session or tab. The description only states what it does, not when it's appropriate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden but only states what the tool does, not how it behaves. It doesn't disclose whether this requires specific permissions, if it returns just the URL string or structured data, error conditions, or dependencies like an open browser tab.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise with just four words, front-loading the core purpose without any wasted text. Every word earns its place, making it easy to parse quickly.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given no annotations, 0% schema coverage, no output schema, and one undocumented parameter, the description is incomplete. It doesn't address key contextual aspects like return format, error handling, or how it interacts with browser state, leaving significant gaps for agent understanding.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, and the description provides no information about the 'tabId' parameter. It doesn't explain what 'tabId' is, how to obtain it, or if it's optional (0 required parameters). The description fails to compensate for the lack of schema documentation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the verb 'Get' and the resource 'current page URL', making the purpose immediately understandable. It doesn't distinguish from siblings like 'navigate' or 'get_page_content', but the purpose is specific enough for a basic retrieval operation.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives like 'get_page_content' (which might include URL) or 'navigate' (which sets URLs). The description lacks any context about prerequisites, such as needing an active browser session or tab.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries full burden for behavioral disclosure. It mentions 'captured' network requests, implying some monitoring or logging context, but doesn't explain how data is captured, retention policies, performance impact, or response format. This leaves significant gaps for a tool that likely interacts with system resources.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise at 5 words, front-loading the core functionality without any wasted text. Every word earns its place by specifying the action and target resource directly.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given 4 parameters with no schema descriptions, no annotations, and no output schema, the description is incomplete. It doesn't address parameter usage, behavioral traits, or return values, making it inadequate for a tool that likely involves complex network data retrieval in a debugging context.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 0% schema description coverage for 4 parameters, the description provides no information about parameters like 'filter', 'limit', 'since', or 'tabId'. It doesn't explain what these control, their formats, or how they affect the output, failing to compensate for the lack of schema documentation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('Get') and resource ('captured network requests and responses'), making the purpose immediately understandable. However, it doesn't differentiate from sibling tools like 'get_all_debug_activity' or 'get_websocket_messages', which appear related to network/debugging activities.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives. With siblings like 'get_all_debug_activity' and 'get_websocket_messages' that might overlap in functionality, the description offers no context about distinctions, prerequisites, or appropriate scenarios for selection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It states what is retrieved but doesn't disclose behavioral traits such as whether this is a read-only operation, if it requires specific permissions, how metrics are formatted, or if there are rate limits. The description is minimal and lacks essential context for safe invocation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise with a single, front-loaded sentence that directly states the tool's purpose without any wasted words. It efficiently communicates the core functionality in minimal space.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the complexity of a performance metrics tool with no annotations, no output schema, and an undocumented parameter, the description is incomplete. It fails to provide necessary details on behavior, parameter usage, or output format, making it inadequate for reliable agent use.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The schema has 1 parameter with 0% description coverage, and the tool description provides no information about the 'tabId' parameter. It doesn't explain what 'tabId' is, how to obtain it, or its role in fetching metrics, leaving the parameter undocumented and unclear.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the verb 'Get' and the resource 'performance metrics', specifying the types as 'timing, memory usage'. This provides a specific purpose, though it doesn't explicitly differentiate from sibling tools like 'get_all_debug_activity' or 'get_network_activity' that might also retrieve performance-related data.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives. The description doesn't mention prerequisites, context, or exclusions, leaving the agent to infer usage from the tool name alone among many sibling tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden but only states the tool gets messages for debugging. It doesn't disclose behavioral traits like whether this is read-only (implied by 'Get'), potential side effects, rate limits, or what 'captured' entails (e.g., buffered data). More context on operation scope is needed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, efficient sentence with zero waste, front-loading the core purpose. Every word earns its place, making it highly concise and well-structured for quick understanding.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given 3 parameters with 0% schema coverage, no annotations, and no output schema, the description is incomplete. It doesn't address parameter meanings, return values, or behavioral details needed for effective use, especially in a debugging context with sibling tools like 'get_network_activity'.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must compensate but adds no parameter information. It doesn't explain what 'limit', 'since', or 'tabId' mean, their units (e.g., 'since' as timestamp), or how they affect message retrieval. This leaves parameters largely undocumented.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('Get') and resource ('captured WebSocket messages'), with a specific purpose ('for LiveView debugging'). It distinguishes from general network activity tools like 'get_network_activity' by focusing on WebSocket messages, though it doesn't explicitly differentiate from all siblings.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides minimal guidance with 'for LiveView debugging', implying usage in debugging contexts, but offers no explicit when-to-use rules, alternatives (e.g., vs. 'get_network_activity'), or exclusions. It lacks context on prerequisites or timing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden but offers minimal behavioral insight. 'Take a screenshot' implies a read operation that captures visual data, but it doesn't disclose critical traits like whether it requires specific permissions, affects browser state, has rate limits, or what happens on failure. For a tool with 3 parameters and no annotation coverage, this is a significant gap.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise with just three words, front-loading the core action without any wasted text. Every word earns its place by directly conveying the tool's purpose, making it efficient and easy to parse.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given 3 parameters with 0% schema coverage, no annotations, and no output schema, the description is incomplete. It doesn't explain parameter roles, behavioral constraints, or return values, leaving gaps for a tool that likely interacts with browser state. More context is needed for effective use.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must compensate but adds no parameter information. It doesn't explain what 'fullPage', 'path', or 'tabId' mean, their defaults, or how they affect the screenshot. With 3 undocumented parameters, the description fails to provide meaningful semantics beyond the basic action.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Take a screenshot' clearly states the action (take) and resource (screenshot), making the purpose immediately understandable. It distinguishes from siblings like 'get_page_content' or 'get_page_text' by specifying visual capture rather than text extraction. However, it doesn't explicitly differentiate from all potential screenshot-related tools, keeping it from a perfect score.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing an open browser/tab), exclusions, or comparisons to siblings like 'get_page_content' for non-visual data. Usage is implied by the action alone, with no contextual boundaries.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions 'Start/restart monitoring' but doesn't clarify what monitoring entails (e.g., real-time streaming, logging), whether it requires specific permissions, if it's destructive or read-only, or what happens on errors. This leaves significant gaps for a tool that likely involves system-level operations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise with a single phrase ('Start/restart monitoring for a tab'), which is front-loaded and wastes no words. Every part of the sentence directly contributes to understanding the tool's purpose, making it efficient and well-structured.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the complexity of a monitoring tool with 2 parameters, no annotations, no output schema, and 0% schema coverage, the description is incomplete. It lacks details on behavior, parameters, return values, and how it integrates with sibling tools, making it inadequate for safe and effective use by an AI agent.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema has 2 parameters with 0% description coverage, and the tool description adds no information about them. It doesn't explain what 'tabId' refers to (e.g., an identifier from 'list_tabs') or what 'types' controls (e.g., monitoring categories like 'console' or 'network'), failing to compensate for the schema's lack of documentation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('Start/restart monitoring') and the target resource ('for a tab'), which provides a specific verb+resource combination. However, it doesn't differentiate from sibling tools like 'get_all_debug_activity' or 'inject_debugging_helpers' that might involve monitoring-related functionality, preventing a perfect score.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives, such as whether it's for initial setup versus ongoing monitoring, or how it relates to sibling tools like 'get_console_logs' or 'get_network_activity'. There's only an implied context of starting monitoring, with no explicit when/when-not instructions or prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden for behavioral disclosure. It states what the tool does but doesn't describe important behavioral aspects: whether this requires prior setup (like start_monitoring), what format the logs return, if there are rate limits, whether logs are cleared after retrieval, or authentication needs. 'Captured' implies some collection mechanism but isn't explained.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, efficient sentence with zero wasted words. It's front-loaded with the core purpose and uses precise terminology. Every word earns its place, making it easy for an agent to parse quickly.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given 4 parameters, no annotations, no output schema, and a browser debugging context with many sibling tools, the description is inadequate. It doesn't explain return format, error conditions, dependencies on other tools, or how this fits into the broader debugging workflow. For a tool that retrieves potentially complex log data, more context is needed.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 75% (3 of 4 parameters have descriptions), so the baseline is 3. The description adds no parameter information beyond what's in the schema - it doesn't explain relationships between parameters (e.g., how since interacts with limit), default behaviors, or parameter constraints. The description doesn't compensate for the 25% gap (tabId lacks schema description).
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Get captured console logs from browser' clearly states the action (get) and resource (console logs from browser). It distinguishes from some siblings like get_javascript_errors (specific error type) and get_network_activity (different resource), but doesn't explicitly differentiate from get_all_debug_activity which might overlap. The purpose is clear but sibling differentiation could be more explicit.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives like get_javascript_errors or get_all_debug_activity. It doesn't mention prerequisites (e.g., whether monitoring must be active), typical use cases, or limitations. The agent must infer usage from the tool name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions 'multi-tab support and debugging' but fails to explain what this entails operationally—such as whether it starts a new browser instance, how tabs are managed, what debugging features are enabled, or potential side effects. This leaves significant gaps for an agent to understand the tool's behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, efficient sentence with no wasted words, clearly front-loading the core functionality. Every part of the sentence contributes directly to understanding the tool's purpose.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (launching a browser with debugging features), lack of annotations, and no output schema, the description is insufficient. It omits critical details like return values, error conditions, how multi-tab support works, and what 'debugging' entails, making it incomplete for effective agent use.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The schema description coverage is 0%, so the description must compensate for the undocumented parameters. It mentions 'debugging', which loosely relates to 'enableDebugLogging', but doesn't explain what 'multi-tab support' means in terms of parameters or how 'headless' mode affects the launch. The description adds minimal semantic context beyond the schema, warranting a baseline score.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('Launch Firefox browser') and key capabilities ('with multi-tab support and debugging'), providing a specific verb+resource combination. However, it doesn't explicitly differentiate from sibling tools like 'create_tab' or 'navigate', which prevents a perfect score.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives like 'create_tab' or 'navigate', nor does it mention prerequisites or exclusions. It merely states what the tool does without contextual usage information.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the action ('List') but doesn't describe what 'active tabs' means, the return format (e.g., list of tab IDs or URLs), or any side effects (e.g., if it refreshes tab data). For a tool with zero annotation coverage, this leaves significant gaps in understanding its behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, efficient sentence ('List all active tabs') with zero wasted words. It's front-loaded with the core action and resource, making it immediately scannable and easy to understand. Every word earns its place by directly contributing to the tool's purpose.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the complexity (a read operation with no parameters) and lack of annotations or output schema, the description is incomplete. It doesn't explain what 'active tabs' entails, the return format, or how it interacts with the browser context. For a tool in a browser automation suite, more context is needed to use it effectively alongside siblings.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The tool has 0 parameters, and the input schema has 100% description coverage (though empty). The description doesn't need to add parameter semantics, as there are none to explain. It appropriately focuses on the tool's purpose without unnecessary parameter details, meeting the baseline for zero-parameter tools.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'List all active tabs' clearly states the verb ('List') and resource ('active tabs'), making the purpose immediately understandable. It distinguishes from siblings like 'close_tab', 'create_tab', and 'set_active_tab' by focusing on listing rather than modifying. However, it doesn't specify the scope (e.g., current browser window vs. all windows), which prevents a perfect score.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing an active browser session), exclusions (e.g., not listing inactive tabs), or related tools like 'get_current_url' for tab details. Without any usage context, the agent must infer when this tool is appropriate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. While 'Close browser and all tabs' implies a destructive action that terminates sessions, it lacks details on effects (e.g., loss of unsaved data, cleanup of resources, error handling). For a tool with no annotations, this leaves significant behavioral gaps.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, efficient sentence with zero waste—'Close browser and all tabs' is front-loaded and directly conveys the core action. Every word earns its place, making it highly concise and well-structured.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (simple destructive action), no annotations, no output schema, and 0 parameters, the description is minimally adequate. It states what the tool does but lacks context on outcomes, side effects, or error conditions, leaving room for improvement in completeness.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The tool has 0 parameters, and schema description coverage is 100% (since there are no parameters to describe). The description does not need to add parameter semantics, so it meets the baseline expectation for a parameterless tool, though it does not explicitly state 'no parameters required'.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Close browser and all tabs' clearly states the specific action (close) and target resources (browser, all tabs). It distinguishes from sibling tools like 'close_tab' (which closes a single tab) and 'create_tab' (which creates rather than closes), making the scope and differentiation explicit.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., whether a browser must be open), exclusions (e.g., avoid if unsaved work exists), or comparisons to siblings like 'close_tab' for partial closure. Usage is implied but not explicitly stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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