Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations provided, so description bears full burden. Discloses purpose but omits details on output (e.g., image format, storage), side effects, or authorization needs. Adequate but not thorough.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, concise and front-loaded with the action. No unnecessary words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Lacks output schema; description does not specify return type or behavior (e.g., base64 image, file path). With only one optional parameter, more detail on the tool's output would enhance completeness.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

100% schema coverage for the single 'name' parameter. Description does not elaborate on the parameter's role or format beyond the schema, meeting the baseline but adding no extra value.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clearly states 'Takes a screenshot of the current page' and explains its purpose for spatial awareness. Distinguishes from sibling tools by positioning it as a fallback when other tools are insufficient.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly advises when to use ('to learn where you are') and when not to ('only use when other tools are not sufficient'), providing clear context for tool selection.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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 discloses behavioral traits: it's a destructive operation (shuts down, terminates) and handles cleanup (browser cleanup, session recording). However, it lacks details on permissions, rate limits, or error handling. The description does not contradict annotations (none exist).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, well-structured sentence that front-loads the core action ('Closes the current Browserbase session') and efficiently adds necessary context (Stagehand cleanup, recording termination). Every word earns its place without redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's complexity (a session-closing operation with no parameters and no output schema) and lack of annotations, the description is mostly complete: it explains what the tool does and its cleanup behavior. However, it could benefit from mentioning potential side effects (e.g., data loss if unsaved) or confirmation of success, slightly reducing completeness.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has 0 parameters with 100% coverage, so no parameter documentation is needed. The description appropriately does not discuss parameters, maintaining focus on the tool's action. Baseline is 4 for 0 parameters, as it avoids unnecessary details.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the specific action ('Closes') and resource ('current Browserbase session'), distinguishing it from siblings like 'browserbase_session_create' (which opens sessions) and 'browserbase_stagehand_*' tools (which operate within sessions). It explicitly mentions 'Stagehand instance' cleanup and session recording termination, providing precise scope.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage context by specifying 'current Browserbase session' and cleanup of 'Stagehand instance', suggesting it should be used after session activities are complete. However, it does not explicitly state when-not-to-use alternatives or prerequisites (e.g., must have an active session).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations, but description details session initialization with config flags and active session update. Lacks disclosure of side effects or permissions, but adequate given tool simplicity.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three concise sentences, front-loaded with purpose and warning, no extraneous content.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Simple tool with single param and no output schema; description covers creation/reuse, initialization, and usage scope fully.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Only parameter sessionId is described in schema; description adds optional reuse and fallback creation behavior, improving clarity beyond schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clear verb 'create or reuse' and resource 'single cloud browser session'. Distinct from sibling 'multi_browserbase_stagehand_session_create'.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicit warning about single vs multi-browser workflows and directs to sibling tool for parallel sessions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations provided; description gives some behavioral context (e.g., atomic actions) but lacks details on side effects, permissions, or reversibility, which is a gap for a tool with no annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two focused sentences with no fluff, front-loaded purpose, and clear structure. Every word adds value.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Covers essential aspects for a simple 2-param tool: purpose, usage constraints, and examples. Lacks return value info, but given no output schema, it's reasonably complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, but description adds value by providing examples for 'action' and explaining the use of 'variables' for sensitive data, enhancing understanding beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool performs actions on web page elements, with emphasis on atomicity and specificity, distinguishing it from siblings like observe or navigate.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly advises actions to be atomic and specific, provides concrete examples of good and bad actions, and suggests using observe if unsure, offering clear when-to-use guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations provided, so description carries full burden. Describes extraction behavior but lacks details on side effects, authentication, or rate limits. However, as a read-only extraction, the description is adequate and does not contradict annotations (none present).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with purpose, but somewhat verbose with repetitive emphasis on specificity. Could be slightly more concise, but still well structured and readable.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Complete for a single-parameter tool with full schema coverage. No output schema, but return values are implied. Lacks error handling details, but overall sufficient for effective use.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Single parameter 'instruction' with 100% schema coverage. Description adds significant value by providing examples, specificity guidance, and warnings against vague instructions, effectively enhancing the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Explicitly states it extracts structured information and text from web pages based on instructions and schema. Clearly distinguishes from sibling tools like observe and act by specifying use cases for data extraction vs. interaction.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides explicit guidance on when to use this tool (scraping data) and when not to (interactive elements), and directly names the alternative tool 'observe' for interactive tasks.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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 discloses the tool's read-only nature (implied by 'Gets') and output format, but lacks details on error handling, rate limits, authentication needs, or whether it returns only active sessions (vs. all sessions). It doesn't contradict annotations, but could be more comprehensive for a tool with no annotation coverage.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two concise sentences with zero waste. The first sentence states the purpose, and the second specifies the return format, both front-loaded and essential for understanding the tool's function.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's low complexity (0 parameters, no output schema, no annotations), the description is reasonably complete. It covers purpose and output, but lacks behavioral details like error cases or session state requirements. With no output schema, it should ideally explain return values more thoroughly, though it does specify the mapping format.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

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% (empty schema). The description adds no parameter-specific information, which is acceptable for a parameterless tool. Baseline is 4 as per rules for 0 parameters, since no compensation is needed.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the specific action ('Gets'), resource ('current URLs of all active browser sessions'), and output format ('mapping of session IDs to their current URLs'). It distinguishes from siblings like browserbase_stagehand_get_url (single URL) and browserbase_session_list (likely lists sessions without URLs).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage context by specifying 'all active browser sessions,' suggesting it's for monitoring or managing multiple sessions. However, it doesn't explicitly state when to use this versus alternatives like browserbase_session_list or browserbase_stagehand_get_url, nor does it mention prerequisites (e.g., sessions must be created first).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It discloses that the tool returns the complete URL including protocol, domain, path, query parameters, and fragments, which adds useful behavioral context beyond the basic action. However, it does not mention potential errors, performance, or dependencies on browser state.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two concise sentences with zero waste. The first sentence states the purpose, and the second elaborates on the return value, making it front-loaded and efficiently structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's low complexity (0 parameters, no annotations, no output schema), the description is fairly complete. It explains the purpose and return value clearly. However, it could be more complete by mentioning potential errors or dependencies, but for a simple read operation, it covers the essentials well.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has 0 parameters, and the schema description coverage is 100%. The description does not need to compensate for any parameter gaps. It appropriately focuses on the output semantics, explaining what the return value includes, which is valuable since there is no output schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the verb 'Gets' and the resource 'current URL of the browser page', specifying exactly what the tool does. It distinguishes from siblings like 'browserbase_stagehand_get_all_urls' by focusing on the single current URL rather than all URLs.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage when the current URL is needed, but does not explicitly state when to use this tool versus alternatives like 'browserbase_stagehand_get_all_urls' or 'browserbase_stagehand_navigate'. It provides basic context but lacks explicit guidance on exclusions or prerequisites.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations provided, so description carries the behavioral burden. It discloses the action (navigate to URL) and adds reliability guidance. However, it doesn't specify loading behavior, timeouts, or error handling, which are minor for a basic navigation tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences with no redundancy. First sentence states the purpose, second gives usage guidelines. Efficient and well-structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple navigation tool with one parameter and no output schema, the description is complete. It covers purpose, usage, and an edge case (unreliable URLs). Minor omission: does not state that navigation changes the current browser context for subsequent actions, but that's implicit.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema already covers 100% of parameters with a description. The description adds value by warning about URL reliability and suggesting a fallback URL, which provides context beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action: 'Navigate to a URL in the browser.' It distinguishes this tool from siblings like screenshot, extract, act, etc., which have different purposes.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly advises when to use the tool (with URLs that are stable and up-to-date) and provides a fallback strategy (use google.com as starting point), effectively guiding the agent's decision.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It explains that the tool returns detailed information about elements (properties, location, interaction capabilities) and implies no side effects. It could mention that it doesn't modify the page state, but it's sufficiently transparent for a read-only observation tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is well-structured, starting with the primary purpose, then usage guidelines, output description, and tips. It is slightly verbose but all sentences add value, avoiding repetition or fluff. It could be trimmed slightly, but overall it is effective.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's simplicity (2 parameters, no output schema), the description is comprehensive. It covers the tool's role in the workflow, what it returns, and how to use it effectively. The description is complete for the agent to understand when and how to use this tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already provides 100% coverage with detailed parameter descriptions. The tool description adds value by emphasizing the need for specific and descriptive instructions, which goes beyond the schema's basic description. This additional context helps the agent craft better instructions.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool observes and identifies interactive elements like buttons and links, distinguishing it from sibling tools like 'extract' and 'act'. It specifies the resource (web page interactive elements) and verb (observe/identify), aligning with the tool's name and purpose.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly tells when to use (before performing actions with the act tool) and when not to use (DO NOT use for extracting text; use extract tool instead). It also advises on instruction specificity, providing clear guidance on prerequisites and alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries full burden. It only discusses action formatting but does not disclose effect on the session, potential failures, permissions, or side effects. Minimal behavioral context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with core purpose, but the advice on atomic actions is repeated unnecessarily ('as atomic and specific as possible' twice). Could be more concise.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema and missing annotations, the description provides adequate guidance for the action parameter but fails to explain session context, error handling, or return behavior. Leaves gaps for a complex interaction tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% with detailed parameter descriptions. The tool description adds value with examples but largely overlaps with schema. Given coverage, a baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states it performs an action on a web page element and emphasizes atomicity. However, it only weakly distinguishes from siblings by appending '(for a specific session)' without explicitly contrasting with the non-session version.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides examples of proper atomic actions and warns against multi-step actions. Also suggests using observe before act if unsure. However, it lacks guidance on when to choose this tool over siblings like browserbase_stagehand_act or multi_browserbase_stagehand_navigate_session.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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. It describes the tool as extracting information, implying a non-destructive read operation. It does not explicitly mention side effects, but for a read-like tool, this is acceptable. It does not contradict any annotations as none exist.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise, front-loaded with the primary purpose, and each sentence adds value. It includes usage guidance, alternatives, and best practices without redundancy or unnecessary detail.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's low complexity (2 parameters, no output schema), the description covers purpose, usage, alternatives, and parameter guidance. It does not describe return format, but this is not critical for extraction tasks. The description is complete enough for an AI agent to understand and use the tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so baseline is 3. The description adds significant value for the 'instruction' parameter by providing detailed guidance, examples, and tips on specificity. For 'sessionId', it merely restates the schema description. Overall, the description enhances understanding beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states that the tool extracts structured information and text from web pages. It specifies the verb 'extracts' and the resource 'current web page'. It also distinguishes itself from the sibling tool 'observe' by clarifying that this tool is for extracting data while 'observe' is for interactive elements.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly states when to use the tool ('scraping data, gathering information, or pulling specific content') and when not to use it ('for interactive elements... use the observe tool instead'). It also provides best practices for crafting instructions and defining a schema, giving clear guidance on effective usage.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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 truthfully describes the retrieval operation without side effects, but does not detail error behavior or prerequisites. For a simple get operation, this is minimally adequate.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences, front-loaded with the purpose, and includes necessary details without wasted words. Every sentence adds value.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the low complexity (single parameter, no output schema), the description is complete enough: it states input, operation, and output format. The mention of session integration adds necessary context for distinguishing from siblings.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% for the only parameter 'sessionId', with a clear description. The tool description does not add further semantics for the parameter beyond what the schema provides, but it does explain the return value context. Baseline score of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool gets the current URL of a browser page and returns the complete URL. It distinguishes from the sibling 'browserbase_stagehand_get_url' by adding '(for a specific session)', making its scope explicit.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies this tool is used when you have a session and need the current URL, providing clear context. It does not explicitly mention when not to use it or compare with alternatives, but the mention of 'session' differentiates it from the similar sibling.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations provided, so description carries full burden. It discloses the navigation action but does not detail error handling, redirects, or wait behavior. The caution about URL stability is helpful.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences with no waste. First sentence states core function; second provides actionable guidance. Efficient and well-structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple navigate tool with 2 parameters and no output schema, the description covers purpose, usage boundaries, and a fallback. Could mention return behavior but is sufficient.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema covers 100% of parameters with descriptions. The tool description adds no additional meaning beyond the schema definitions for 'url' and 'sessionId'.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Navigate to a URL') but does not distinguish from the sibling 'browserbase_stagehand_navigate' which has similar purpose. The guidance about URL reliability adds context.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly states when to use the tool (confident, up-to-date URLs) and when to fall back to a generic starting point (Google), providing clear context and alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries full burden. It explains that the tool returns 'detailed information about the identified elements including their properties, location, and interaction capabilities,' which is a high-level behavior overview. While it lacks specifics on return format or edge cases, it sufficiently discloses the tool's behavioral characteristics for an observe-type tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is moderately long but well-structured. It front-loads the core purpose, followed by usage guidelines, and then parameter-level advice. Every sentence adds value, though some minor redundancy exists (e.g., emphasizing specificity twice). Overall, it earns its length.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the absence of an output schema and annotations, the description covers the essential aspects: purpose, usage, parameter guidance, and expected output (detailed element info). It is complete enough for an observe tool, though it could optionally mention error scenarios or performance implications.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so baseline is 3. The description adds significant value beyond the schema by providing detailed instructions for the 'instruction' parameter, including examples of good vs. bad instructions. It also explains the 'returnAction' parameter, clarifying its purpose. This extra context raises the score above baseline.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: 'Observes and identifies specific interactive elements on the current web page that can be used for subsequent actions.' It uses specific verbs (observes, identifies) and resource (interactive elements), and explicitly distinguishes from sibling tools like extract and act.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit when-to-use guidance: 'Use this tool when you need to locate elements before performing actions with the act tool.' It also states what not to use it for: 'DO NOT use this tool for extracting text content or data - use the extract tool instead.' This clearly distinguishes from siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description fully discloses the destructive behavior: termination, freeing resources, and the irreversibility of closing a session (noted in parameter description). It does not mention potential permissions or side effects, but the core behavior is clear.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three concise sentences with no redundancy. It front-loads the purpose and follows with usage guidance and a critical warning. Every sentence adds value.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple close operation with one parameter and no output schema, the description covers all necessary aspects: what it does, when to use, how to get the ID, and the irreversible nature. It is fully complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema provides 100% coverage for the single parameter 'sessionId'. The description adds extra context: where to find the ID (from session_list) and a warning about irreversibility. This goes beyond the schema's basic type and requirement.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: cleaning up a parallel session by terminating the browser, ending the Browserbase session, and freeing cloud resources. It distinguishes itself from sibling tools like browserbase_session_close (single session) and multi_browserbase_stagehand_session_list (listing).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly tells when to use the tool ('when finished with a session') and emphasizes its necessity for responsible multi-session automation. However, it does not explicitly mention when not to use or compare with alternatives like browserbase_session_close.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Without annotations, the description carries full burden. It discloses that the session is isolated with independent cookies, authentication, and state. However, it does not mention potential side effects like cost limits or asynchronous behavior, though the provided details are sufficient for typical use.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is 5 sentences, front-loaded with purpose and usage. It is efficient but could be slightly tighter; some examples could be condensed. Still, it is well-structured and avoids redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description explains when to use and behavioral traits, but it does not mention what the tool returns (e.g., session ID). Given no output schema, the return value is a gap. Also, no information about error handling or asynchronous behavior. Adequate but not fully complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% with both parameters well-documented. The description adds value by providing context (e.g., 'Highly recommended' for name), but the main description does not elaborate further. Baseline 3 is appropriate as schema already covers semantics.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Create parallel browser session for multi-session workflows' with specific use cases (parallel scraping, A/B testing, multiple user accounts). It distinguishes from sibling tools by noting that it pairs with session-specific tools (ending with '_session'), making its purpose unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly states when to use: 'Use this when you need multiple browser instances running simultaneously' and provides concrete examples. Also advises to pair with session-specific tools, offering clear guidance on proper usage and alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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 effectively discloses behavioral traits: it's a read-only tool (implied by 'track' and 'shows'), essential for monitoring and debugging, and critical for multi-session management. However, it doesn't mention potential limitations like rate limits or authentication needs, though these might be less relevant for a list tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is appropriately sized and front-loaded, starting with a critical warning and key purpose. Each sentence adds value, such as listing session details and specifying use cases, though it could be slightly more streamlined by reducing exclamation points and repetitive emphasis.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's complexity (multi-session management), lack of annotations, and no output schema, the description is largely complete. It explains the tool's role, when to use it, and what information it provides. However, it doesn't detail the output format or potential errors, which could be helpful for an agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has 0 parameters with 100% coverage, so no parameter documentation is needed. The description appropriately focuses on usage and context without redundant parameter details, earning a baseline score of 4 for zero-parameter tools that avoid unnecessary information.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose with specific verbs ('track', 'shows') and resources ('all active browser sessions'), explicitly distinguishing it from sibling tools by emphasizing it's for multi-session management and listing session details like IDs, names, ages, and Browserbase session IDs. It avoids tautology by not just restating the name.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit usage guidance: it states 'ONLY WORKS WITH MULTI-SESSION TOOLS!' and specifies when to use it ('frequently to monitor parallel automation workflows', 'verify sessions are running', 'get session IDs for session-specific tools'), with clear context for debugging and resource management in multi-browser scenarios, distinguishing it from single-session tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.