Web Fetch

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 effectively describes key behaviors: content extraction for HTML (extracts text), support for multiple formats (JSON, plain text), security restrictions (default trusted domains only), and the ability to override security with 'allow_any_domain'. However, it doesn't mention potential rate limits, error handling, or response structure details, leaving some behavioral aspects uncovered.

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 efficiently structured in three sentences that each serve a clear purpose: stating the core function, listing supported formats, and explaining security behavior with a cautionary note. There's no redundant information, and it's appropriately sized for the tool's complexity, 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.

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

For a tool with 3 parameters, 100% schema coverage, but no annotations or output schema, the description does well by covering purpose, usage guidelines, and key behaviors. It adequately explains what the tool does and when to use it, though it could benefit from more detail about output format or error cases to be fully complete given the lack of output schema.

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 description coverage is 100%, so the schema already documents all three parameters thoroughly. The description adds some context by explaining the security implications of 'allow_any_domain' ('use with caution') and mentioning content type support, but doesn't provide additional semantic meaning beyond what the schema descriptions already cover for each parameter.

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 'fetch' and resource 'content from a URL', specifying the action and target. It distinguishes this tool from siblings like 'web-search' by focusing on direct URL content retrieval rather than search functionality, making the purpose specific and well-differentiated.

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 guidance on when to use the tool: for fetching content from URLs, with specific content types supported (HTML, JSON, plain text). It also includes a clear cautionary note about the 'allow_any_domain' parameter, advising 'use with caution' for non-trusted domains, which helps the agent understand security implications and appropriate usage contexts.

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