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

With no annotations provided, the description must disclose behavioral traits. It does say 'Body discarded,' which is a useful behavioral note, but it omits what happens with the other 8 parameters (e.g., are they validated? discarded? cause side effects?). The description only covers the URL case, leaving the tool's full behavior opaque.

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 phrases) and front-loads the primary action. However, its brevity comes at the cost of completeness — it omits the tool's actual scope (as seen in the schema) and provides no usage context. It is not wasteful, but it fails to earn its place by being misleadingly narrow.

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?

This is a 9-parameter tool with no output schema and no annotations. The description covers only one use case (library docs URL) and says nothing about the other parameters, return format, or when to use it. An agent would have no idea how to correctly invoke this tool for the other 8 parameters or what to expect. This is severely incomplete.

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% — every parameter has a description (e.g., 'Git ref name; discarded after the shape check'). The tool description adds no parameter-specific information beyond what the schema already provides, so the baseline of 3 is appropriate. It neither helps nor hurts.

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 specific action (get HTTP status for a library docs URL) and that the body is discarded, which is clear in isolation. However, it directly conflicts with the input schema, which lists 9 unrelated parameters (city, feed, json, zone, etc.), implying the tool does far more than check library docs URLs. This mismatch makes the purpose ambiguous and misleading for an agent deciding which tool to call.

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 no guidance on when to use this tool versus siblings like fetch-status, browser-url-ok, or normalize-url. It doesn't mention alternatives, conditions for selection, or exclusions. An agent has no basis to choose this over closely related tools.

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