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

With no annotations, the description must fully disclose behavioral traits. It only states that the tool returns an HTTP status and discards the body, which implies a read-only HEAD-like operation. However, it does not explain side effects (e.g., network access, rate limits, auth requirements), nor the behavior when non-URL parameters like city or json are provided. The description is severely lacking in transparency for a tool that appears to handle diverse input types.

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 clear sentence with no filler, which is concise and front-loaded. However, it is under-specified for a tool with 9 parameters and no other context. While brevity is a virtue, the sentence omits crucial information about the parameters and usage, making it insufficient. It earns a pass for being short, but the structure lacks the necessary detail.

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?

Given the tool's complexity (9 parameters, no output schema, no annotations, and 28 siblings), the description is grossly incomplete. It does not explain how the parameters map to the operation, what the return value looks like (only 'HTTP status'), any error behavior, or how this tool integrates with the broader tool ecosystem. An agent cannot reliably select or invoke this tool based on the provided description alone.

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 schema already covers 100% of parameters with descriptions, so the baseline is 3. However, the tool description does not add meaning beyond the schema; instead, it creates confusion by focusing on a 'public library docs URL' while the parameters include unrelated fields like city, feed, json, and zone. The schema descriptions themselves are terse ('discarded after the shape check'), and the tool description does nothing to clarify how these parameters relate to the stated operation. The description actually weakens the semantic understanding, dropping the score below baseline.

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 (return HTTP status) for a specific resource (public library docs URL), which provides some initial clarity. However, the tool name 'lib-docs-hint' and the description do not align with the 9 parameters, many of which are unrelated to a library docs URL (e.g., city, feed, json, zone, query). This makes the actual purpose ambiguous and fails to distinguish the tool from siblings like fetch-status or browser-url-ok, which also handle URLs. The description is too narrow and misleading relative to the parameter set.

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 usage guidance is provided. The description does not mention when to use this tool versus any of its 28 siblings, nor does it specify any conditions or prerequisites. An agent is left to guess when this tool is appropriate and how it differs from tools like fetch-status, normalize-url, or web-fetch.

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