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

With no annotations, the description carries full responsibility for behavioral disclosure. It mentions 'Body discarded,' which is a useful trait, but it omits other behaviors like redirect handling, timeouts, authentication needs, or rate limits. It also does not clarify what happens when multiple parameters are provided, or whether the tool performs a network request at all. The description is too sparse to be transparent.

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 concise sentence that front-loads the core action and the body-discard note. It is efficient with no filler. However, it is so brief that it borders on under-specification for a tool with 9 parameters, but as a standalone description it is well-structured and to the point.

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 has 9 optional parameters and no output schema, the description is incomplete. It only addresses the URL status aspect, leaving the other parameters unexplained in context. An agent would not know why 'city' or 'zone' are relevant, or how they interact with the 'lib-docs' purpose. The description fails to cover the full scope of the tool's capabilities.

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 provides 100% coverage with descriptions for all 9 parameters, so the baseline is 3. The description adds no parameter-specific meaning beyond the schema—it only mentions 'HTTP status for a public library docs URL' without linking to the parameters. It does not explain how ref, city, feed, host, json, path, zone, or query relate to the tool's operation, so it neither adds nor detracts from the schema's coverage.

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 verb and resource: 'HTTP status for a public library docs URL.' It clarifies that the body is discarded, implying a status-only check. However, it does not explain what 'lib-docs' means or differentiate this from siblings like fetch-status, browser-url-ok, or normalize-url, all of which also deal with URLs. The purpose is clear at a surface level but vague about the specific role of this tool.

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 its many siblings. There is no mention of alternatives, conditions, or exclusions. An agent would have to infer usage from the name and description, which is insufficient given the crowded sibling list.

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