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

No annotations are provided, so the description carries the full burden. The description mentions 'HEAD' (implying no body download) and 'status only', which is a hint, but it doesn't disclose that most parameters are ignored/discarded, which is a significant behavioral trait. Also, the description doesn't address error handling, redirections, 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 a single short sentence, which is concise and front-loaded with the main action. It earns its place, but given the complexity of the parameter set and the tool's odd behavior, it is under-specified, so a 4 is appropriate.

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?

With 9 optional parameters, no output schema, and no annotations, the description is severely incomplete. It doesn't explain why so many parameters are accepted or how they relate to the operation relative to siblings. An agent would be uncertain about how to construct a valid call and what the response would look like.

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 100% because each parameter has a description, but those descriptions are largely misleading for this tool: they suggest the parameters actually do something (e.g., 'validate JSON', 'normalize URL'), while the tool description says it only returns status. Many parameters are described as 'discarded', but the purpose of accepting them is unclear. The description does not add value beyond the schema, and in fact contradicts the schema's implied semantics.

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 states a clear action ('HEAD a public URL') and the expected output ('return status only'), but the tool name is 'fetch-status' and the description doesn't clarify how this differs from siblings like 'browser-url-ok' or 'web-fetch'. The description is somewhat generic and could apply to multiple 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 says 'public URL' implying it should be used only for public URLs, but it doesn't explicitly state when to use this tool instead of alternatives like 'browser-url-ok' or 'web-fetch'. No exclusions are given, and the presence of many unrelated parameters (city, feed, json) without guidance is confusing.

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