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

The description discloses that the body is not returned, which is a useful behavioral detail. With no annotations provided, it does not fully cover side effects such as network access, redirects, timeout behavior, or rate limiting, but the core behavior of fetching a URL is implied by the tool name.

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 short sentences, front-loads the primary purpose, and contains no filler or redundant wording. It is appropriately concise for the stated behavior.

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?

Despite the simple stated purpose, the nine-parameter schema is highly confusing and the description does not reconcile it with the tool's function. There is no explanation of output format beyond status/content type, how parameters relate to each other, or which parameter is the main input, leaving an agent without enough context to invoke the tool reliably.

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 tool description only relates to a URL, but the schema contains nine optional parameters covering git refs, cities, feeds, hosts, JSON, file paths, timezones, and search queries. The parameter descriptions are largely unrelated to 'web-fetch' (e.g., 'url' is described as 'HTTPS URL to normalize or cite', not to fetch), so the description fails to explain which parameters are actually used or how they interact.

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 that the tool returns HTTP status and content type for a public URL and that the body is discarded. It is specific about the resource type ('public URL') and the output scope, though it lacks an explicit verb and does not distinguish itself from sibling tools by name.

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?

'Body discarded' implies the tool is for cases where only status/content type are needed, and 'public URL' hints at a public-only scope. However, it does not explicitly state when to prefer this tool over sibling tools such as fetch-status or browser-url-ok, nor when not to use it.

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