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

With no annotations provided, the description carries the full burden, and 'Body discarded' is a valuable, non-obvious behavioral disclosure. It also clarifies that the tool works on public URLs, implying no authentication. It does not detail redirect handling or error behavior, but the key limitation is surfaced.

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, compact sentence with the primary output front-loaded and the critical limitation stated immediately. Every word earns its place, and no unnecessary detail is included.

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 has nine optional parameters and no output schema, yet the description only addresses 'a public URL.' It does not explain which parameter to populate, whether the tool accepts multiple input types, or what the return format looks like. The mismatch between the narrow URL description and broad schema makes the description incomplete for an 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 description coverage is 100%, so the schema already documents every parameter. The description adds general context about public URL usage and body handling but does not add meaning beyond the schema. Baseline 3 is appropriate.

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 communicates the core function: retrieve the HTTP status and content type for a public URL, with the body discarded. It is specific enough to distinguish web-fetch from generic URL tools, though it does not explicitly name or contrast sibling tools.

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 only a minimal usage context: public URL and body discarded. It offers no guidance on when to choose this tool over siblings such as fetch-status, browser-url-ok, or playwright-url-ok, and it does not state exclusions or conditions clearly.

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