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 discloses the state-changing navigation and return of a snapshot, but it does not describe behavior when history is empty, how it handles pending loads, or the structure of the returned snapshot.

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?

A single sentence leads with the action and ends with the expected result, containing no filler or redundant phrasing.

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 zero-parameter tool, the description conveys the operation and return value sufficiently. It is slightly incomplete on edge-case behavior and snapshot specifics, but these gaps are minor given the tool's simplicity.

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 takes zero parameters, so schema coverage is complete and no parameter-level explanation is needed. The baseline of 4 applies because there is nothing for the description to add.

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 names a specific verb-resource pair ('Go back one page in the current tab's history') and states the outcome ('return the new snapshot'). This clearly distinguishes it from sibling navigation and interaction tools like click, scroll, and browse.

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 usage condition is clear: use this tool when the agent needs to move one step backward in the current tab's history. It does not explicitly mention alternatives or edge-case exclusions, so it stops short of a 5.

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 carries the full burden and does well: it discloses that the tool autonomously picks and executes clicks/fields, operates at roughly 300 ms per step, returns several statuses, and requires two API keys. It could add side-effect warnings for actions like form submissions or purchases, but it is substantially transparent.

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 compact and well structured: purpose first, then usage mode, return values, and prerequisites. Each sentence earns its place without repeating schema information unnecessarily.

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 there is no output schema, the description usefully enumerates the return statuses and final-page fields, and it names the required API keys. It could further clarify the meaning of statuses like blocked/stuck/budget, but the overall picture is serviceable for a complex 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 coverage is 60%, and the description adds useful semantics for `url` by explaining that omitting it continues in the current tab. However, it does not add meaning for `timeout_s` or `max_actions`, leaving those to their names and schema defaults.

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 a specific capability: accomplishing a plain-English goal on a web page end to end via an autonomous Chrome agent. It also distinguishes itself from lower-level siblings by saying 'One call replaces a whole click-by-click session.'

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 gives clear usage context: pass `url` to open a page or omit it to continue in the current tab, and use it for end-to-end goals rather than individual click/type operations. It does not explicitly name alternatives or give when-not-to-use cases, so it stops short of a 5.

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 tasks run in parallel tabs and that results are returned compactly. It does not mention side effects, error handling, or rate limits, but for a straightforward browser automation tool these are not critical. The disclosed behavior aligns with expectations.

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 concise sentences with zero waste. The first sentence front-loads the core function and output, the second gives usage context. No redundancy or filler.

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 multi-task browsing tool, the description covers the essential aspects: what it does, how it operates (parallel), and what to expect (compact results). It does not detail the return structure or all parameter semantics, but the schema provides constraints and defaults. The description is adequate for an agent to understand the tool's purpose and call it 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 description coverage is 0%, so the description must compensate. It mentions 'url+goal tasks' which clarifies the structure of the 'tasks' parameter, but it does not explain 'concurrency' or 'max_actions'. The description only partially compensates for the missing schema documentation.

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 states a specific verb (run), resource (several url+goal tasks), mode (in parallel tabs), and output (return all results, compact). It also explicitly frames usage as 'checking many sites or pages at once', which clearly distinguishes it from sibling tools like 'browse' that handle a single page.

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 clear context with 'Use for checking many sites or pages at once', which implies it is for multi-task scenarios. However, it does not explicitly name alternatives or state when NOT to use it, though the sibling list (e.g., 'browse') makes the distinction apparent.

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 carries the burden and does disclose the return behavior ('Returns the new snapshot'). However, it does not mention side effects such as navigation, page changes, invalidating the previous snapshot, or failure conditions, leaving some behavioral uncertainty for a mutating 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 short sentences deliver the action, the source of the index, and the return value with no filler. The phrasing is front-loaded and every word contributes information.

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 one-parameter tool with no output schema, the description covers the core invocation and return value, and even points to the prerequisite browse/snapshot state. It is incomplete only around edge cases such as stale snapshot, invalid index, or click failures, which a competent agent would have to discover elsewhere.

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?

Despite zero schema description coverage, the description explains that 'index' refers to an element's position in the last snapshot/browse, which is essential meaning the schema lacks. It stops short of specifying whether the index is zero-based or one-based, but this is a minor omission for a single-parameter tool.

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?

Opens with the imperative 'Click', names the resource ('element [index]'), and anchors it to 'the last snapshot/browse', which makes the operation distinct from sibling tools like type_text or press_key. A single sentence gives an agent enough to know exactly what action is being described.

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 the prerequisite context: the element comes from 'the last snapshot/browse', so an agent knows to call browse or snapshot first. It does not spell out when not to click versus using alternatives, but the one-parameter action is unambiguous enough.

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 of behavioral disclosure. The description only states what it does (closes the tab) but does not mention whether this is destructive, whether it requires confirmation, or whether the tab's state is lost. Since closing a tab is a mutation with potential data loss, this is a significant omission.

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, concise sentence that conveys the complete action. There is no unnecessary information or repetition, and the verb is front-loaded. Perfectly 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?

For a tool with no parameters and a simple action, the description is largely complete. It identifies the target (current tab) and the action (close). However, given the lack of annotations, it could note the destructive nature of closing a tab, but the tool's simplicity and lack of parameters make it adequate. Overall, an agent can call it correctly without ambiguity.

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 zero parameters, which sets a baseline of 4 per the rubric. Since there are no parameters to explain, the description does not need to add parameter details. It correctly omits any parameter discussion.

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 'close' and the resource 'current tab', making the action unambiguous. It is distinct from sibling tools (click, browse, back) as none of them perform closing. A specific action with no ambiguity.

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?

There is no explicit guidance on when to use this tool versus alternatives. However, the action is self-explanatory and the context of 'current tab' implies it is used for closing a browsing tab. No exclusions or alternatives are mentioned, so the usage context is implied rather than explicit.

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 usefully discloses that providing `goal` triggers navigation before extraction and that output is schema-driven. However, it does not clarify what happens when `url` is supplied without `goal`, whether extraction leaves page state changed, or what error/response behavior to expect.

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 short sentences, front-loaded with purpose, followed by behavioral mode and a concrete example. Every sentence earns its place and there is no filler or repetition of schema 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?

With no annotations and no output schema, the description must do more than it does. It covers the core purpose and main usage pattern, but the relationship between `url`, `goal`, and the current page is underspecified, which is material for correct invocation.

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 67%, so the schema documents `goal` and `schema` but not `url`. The description adds value by explaining `goal`'s conditional behavior and giving a concrete `schema` example, but it leaves the `url` parameter ambiguous and does not fully compensate for that gap.

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 first sentence, 'Get structured JSON from a page,' states a specific verb, resource, and output type. This clearly differentiates it from navigation and visual siblings like click, browse, snapshot, and screenshot, so an agent can identify it as the extraction tool.

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 gives explicit conditional usage: with `goal` it browses first; without it, it extracts from the current page. It also tells the caller to describe the desired shape in `schema`. It does not explicitly name alternative tools or exclusion cases, so it falls just short of a 5.

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 behavioral burden. It does disclose that the tool returns a new snapshot after pressing the key, which is valuable. However, it does not mention potential side effects such as navigation, form submission, or the requirement that the intended element have focus.

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 short sentences, each earning its place: the first states the action and valid inputs, the second states the return value. The content is front-loaded and contains no filler.

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 single-parameter tool with no output schema and no annotations, the description covers the core requirements: what the tool does, what input values are supported, and what is returned. It could be slightly more complete by noting focus requirements or post-keypress page changes, but the essential information is present.

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 only defines 'key' as a string with zero percent description coverage, so the description must compensate. It does so thoroughly by enumerating the valid special keys and clarifying that a single character is also accepted, removing ambiguity about expected input format.

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 uses a specific verb (press), states the resource (current tab), and enumerates the exact set of accepted keys. This clearly distinguishes it from siblings like click (mouse action) and type_text (multi-character text input).

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 key list and 'single character' wording imply this is for discrete key presses, but the description does not explicitly say when to use this tool versus type_text or click, nor does it mention any exclusions or alternatives. Usage context is implied rather than directly stated.

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 and no output schema, the description carries the full burden of explaining behavior. It discloses that the result is a JPEG screenshot of the current tab, but does not say how the image is returned (e.g., path vs. data URL), whether it captures the visible viewport or full page, or whether any side effects occur.

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 tightly worded sentence: 'JPEG screenshot of the current tab.' Every word earns its place, and the key facts are front-loaded without any filler.

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 zero-parameter tool, this is nearly sufficient, but it leaves gaps that an agent must guess: the return format of the screenshot and the distinction from the sibling 'snapshot' tool. The absence of an output schema makes these gaps more significant.

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 zero parameters, so there is no parameter semantics to document. The schema coverage is trivially 100%, and the description adds relevant context by specifying the JPEG output format.

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 states a specific action (screenshot), a specific resource (current tab), and the output format (JPEG). The tool is easy to understand, but it does not distinguish itself from the sibling tool 'snapshot', which could plausibly overlap in function.

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?

There is no guidance about when to use this tool versus alternatives like 'snapshot', 'browse', or 'extract'. The description only says what it does, not when an agent should prefer it.

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 carries the burden of explaining behavior. It discloses that scrolling occurs in the current tab and that a new snapshot is returned, but it does not mention scroll increments, end-of-page behavior, or handling of lazy-loaded content. This is adequate but not richly transparent.

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, front-loaded sentence with no filler. Every word contributes to stating the action and the return 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 tool with one optional parameter and no output schema, the description covers the core action and result. It omits edge cases and boundary behavior, but the low complexity means this is unlikely to block correct invocation.

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 only parameter, direction, is referenced in the description ('down (or up)') with values matching the schema enum. However, with 0% schema description coverage, the description adds little beyond restating the enum and does not explain default behavior or scrolling amount.

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 uses a specific verb and resource ('Scroll the current tab down (or up)') and states the returned result ('return the new snapshot'). It is distinguishable from siblings like click, type_text, and browse, though it does not explicitly contrast itself with the related snapshot tool.

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?

No guidance is provided about when to use scroll versus browse, snapshot, or extract. The description only states the action itself, leaving the agent to infer appropriate usage from the tool name and sibling list.

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 performance (~0.5s), model-free operation, lack of API key requirements, and the nature of the returned content. It does not explicitly mention whether opening a URL navigates/changes the current tab, which is a minor side-effect gap.

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 compact and front-loaded. It starts with the core value proposition, then covers parameter behavior, and ends with the API-key note. Every sentence adds necessary information with no filler.

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 one-parameter tool with no output schema, the description provides enough to invoke it correctly: what it returns, how to use the parameter, expected speed, and authentication requirements. The missing navigation side-effect detail is minor and does not prevent correct 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?

Schema coverage is 0%, so the description must explain the only parameter, url. It does: 'Pass a url to open it, or omit to re-read the current tab.' This is clear and complete for a single optional string parameter, though it stops short of specifying URL formats or edge cases.

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 names a specific action ('read'), a target resource ('a page'), and a distinctive return type ('visible text plus numbered interactive elements'). This clearly separates it from siblings like screenshot, extract, and browse, even without naming them.

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?

It gives operational guidance: pass a URL to open it, or omit to re-read the current tab. It also hints at downstream usage with click/type_text. However, it does not explicitly explain when to choose snapshot over browse or extract, so selection guidance is mostly implied rather than stated.

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 present, the description carries the behavioral burden. It discloses three meaningful behaviors: content replacement, optional Enter submission, and returning a new snapshot. It omits edge-case behaviors like invalid index handling or whether the element must be visible, but the disclosed behaviors are substantive for a simple 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 compact and front-loaded: the main action appears first, followed by the optional submit behavior and return value. Every clause earns its place with no filler or repeated schema 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?

For a simple three-parameter tool with no output schema, the description covers the core action, replacement semantics, optional submission, and return snapshot. Minor gaps such as behavior on invalid indexes or focus requirements keep it from being fully complete, but nothing essential for a normal call is missing.

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 only 33%, so the description needs to compensate. It gives useful context for index ('editable element [index]') and text ('Type text'), and restates the submit behavior. However, it adds little beyond the schema's own submit description and does not clarify index format, zero-based indexing, or text handling 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?

States a clear verb+resource pair ('Type text into editable element [index]') and distinguishes itself from siblings like press_key by targeting an element and typing text rather than simulating a key press. The parenthetical 'replaces its content' further sharpens the tool's exact behavior.

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 is for entering text into an editable element, but it never explicitly says when to use this tool versus alternatives such as press_key or click. No exclusions or conditional routing are provided, so the agent must infer the appropriate context.

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