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 the basic read-only nature and output format (titles/references), but omits behavioral details like permission requirements, privacy considerations, or whether tab references are persistent IDs.

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?

Single sentence, front-loaded with the action verb, and zero wasted words. Every component earns its place by defining scope ('all open tabs'), location ('user's browser'), and output ('titles and tab references').

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 single-parameter tool without output schema, the description adequately explains what the tool returns. It could be improved by mentioning the URL inclusion option described in the schema, but it covers the core functionality sufficiently.

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%, establishing a baseline of 3. The description does not mention the includeUrl parameter or its default behavior (URLs excluded), leaving all parameter semantics to the schema itself.

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 ('List') and resource ('open tabs'), and distinguishes from siblings by specifying it returns 'titles and tab references' (metadata) rather than content, clearly differentiating it from read_tab_content.

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?

While the description implies usage by stating it returns tab references (suggesting it's for discovery before reading), it lacks explicit guidance on when to use this versus read_tab_content or workflows like 'use this first to get tab IDs'.

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 of behavioral disclosure. It clearly indicates a side effect (creating a new tab) and implies user-facing presentation, but omits execution details such as whether the call blocks until the page loads, error handling for invalid URLs, or whether the tab persists after the session.

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?

Single sentence of 13 words with the action front-loaded. Every word earns its place—'present content' and 'enable user interaction' efficiently convey the dual use cases 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 simplicity (single required parameter, no output schema, no nested objects), the description adequately covers the essential information needed for invocation. It appropriately omits unnecessary details while capturing the core user-facing purpose.

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%, providing complete documentation for the 'url' parameter. The description references the URL but does not add semantic meaning beyond the schema (e.g., no mention of supported protocols, relative vs absolute URLs, or validation rules), meriting the baseline score.

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 (Open), resource (URL), and location (new tab), and clearly distinguishes from siblings list_tabs (which lists existing tabs) and read_tab_content (which reads from tabs) by emphasizing the creation of a new browsing 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?

Provides clear context for when to use the tool ('to present content or enable user interaction with webpages'), giving the agent criteria for selection. However, it does not explicitly contrast with sibling tools or state when NOT to use it (e.g., when extraction without opening is needed).

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 of behavioral disclosure. It establishes this is a read operation targeting browser content and specifies the tab selection logic. However, it omits details about the return format (plain text vs. HTML vs. structured data), content size limits, or whether the operation affects 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?

Two well-structured sentences with zero waste. The first sentence front-loads the core purpose; the second provides essential parameter guidance. Every word earns its place—no filler, no redundancy, and no unnecessary verbosity.

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 100% schema coverage for the 2 parameters, the description adequately covers inputs. However, with no output schema provided, the description could be improved by briefly indicating the return format (e.g., extracted text content) to complete the picture for the 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?

Schema coverage is 100%, establishing a baseline of 3. The description adds valuable semantic context by specifying that the ID comes from 'list_tabs output,' which helps the agent understand the tool relationship. It does not add significant detail beyond the schema for startIndex or ID format syntax.

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 ('Get readable content') and resource ('tab in the user's browser'). It effectively distinguishes from sibling tools by explicitly referencing 'list_tabs output' for the ID parameter, clarifying this reads existing content rather than opening new tabs.

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 clear guidance on when to provide the ID parameter (to read a specific tab) versus when to omit it (for the active tab). Mentions the dependency on list_tabs for obtaining valid IDs. Lacks explicit 'when not to use' guidance contrasting with open_in_new_tab, though this distinction is relatively clear from the verb choices.

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