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

With no annotations, the description carries the full burden of behavioral disclosure. It does disclose that the body is discarded and that only status/content type are returned, which is useful. However, it fails to disclose the behavior for the other eight parameters (e.g., city, json, query) which are described in the schema as 'discarded after' checks but are not mentioned in the description at all. No side effects, authentication, or rate limits are mentioned.

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 (two sentences) and front-loaded with the primary purpose. It wastes no words. However, it is so brief that it omits essential context, which moves it from 'appropriately concise' to 'under-specified.' Still, for conciseness alone it earns a 4, though the lack of structure for a multi-parameter tool is a flaw.

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 9 parameters, no annotations, and no output schema, yet the description only addresses one parameter (url). It gives no explanation of how the other parameters are used, what the expected response format is, or what conditions trigger the checks. An agent would be unable to correctly invoke this tool for any parameter other than url, and even for url the behavior is only partially described. This is severely incomplete for a tool of this complexity.

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 each parameter already has a description. The tool description itself adds no parameter semantics—it does not explain how the parameters relate to the tool's purpose. Baseline of 3 is appropriate because the schema covers the parameters, but the description adds no value beyond that and leaves the relationship between parameters and tool behavior unclear.

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 core function: obtaining HTTP status and content type for a public URL, and notes the body is discarded. This distinguishes it from generic 'fetch' tools and gives a specific verb+resource. However, it does not differentiate from siblings like fetch-status or browser-url-ok, and the presence of unrelated parameters (city, json, zone) introduces ambiguity about the tool's full scope.

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?

No guidance is provided on when to use this tool versus alternatives. The description does not mention any conditions, prerequisites, or exclusions. An agent would have no basis to choose web-fetch over fetch-status or normalize-url, especially given the tool's broad parameter set.

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