fetch_url

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

No annotations are provided, so the description must carry the full burden. It only describes the basic action and return format but omits important behavioral traits such as rate limits, size constraints, redirect handling, error behavior, or that the operation is read-only.

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, listing Args and Returns without unnecessary details. It is front-loaded with the key action. A single sentence of added complexity would not harm, but it is already efficient.

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 tool is simple with one parameter and an output schema, and the description covers the core purpose and return type. However, it lacks completeness regarding behavioral aspects like error handling and content type limitations, which are not compensated by annotations.

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%, and the description adds minimal context: 'url: The URL to fetch and convert to markdown.' This clarifies the parameter's role but does not specify required formats or allowed protocols, providing only marginal value 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?

Description clearly states the tool fetches content from a URL and converts to markdown. This distinct verb+resource pair differentiates it from sibling search tools that return lists instead of 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?

Context is clear: use this tool when you have a specific URL to retrieve. Sibling tools are search-oriented, implying no overlap. However, no explicit when-not-to-use instructions or alternatives are provided.

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