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 explicitly mentions full JavaScript execution for React/SPAs and aggressive stripping of images/media, including base64, to save context tokens. This gives substantial insight into the tool's behavior, though it does not cover error handling or rate limits.

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 long, front-loaded with the primary action, and every phrase adds value. It is information-dense with no wasted words, 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?

Given the absence of an output schema, the description clarifies that the tool returns extracted main text content and highlights key behaviors like JS execution and media stripping. It does not mention template usage or pagination, but those are fully described in the parameter schema, making the overall picture complete enough.

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 covers 100% of the parameters, so the baseline is 3. The description adds context about aggressive media stripping and base64 handling, which goes slightly beyond the schema's block_media parameter description. No major parameter semantics are missing.

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 fetches and extracts the main text content from any webpage, using the specific verb 'Fetch and extract'. This distinctly differentiates it from the sibling 'websearch' tool, which would be used for searching rather than fetching a specific URL.

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 for retrieving content from a known URL, while the sibling 'websearch' is for finding URLs. It provides clear context ('any webpage') but does not explicitly state when to choose this over alternatives or mention exclusion cases.

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