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

With no annotations, the description must disclose behavioral traits. It only mentions 'Body discarded' for the URL case, but fails to explain that other parameters (city, json, zone) likely trigger entirely different behaviors. The tool's actual operation is 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 extremely short (two clauses), but it is under-specified rather than efficiently concise. It omits essential context about the tool's multi-parameter nature, so the brevity harms usefulness rather than aiding clarity.

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?

For a tool with 9 parameters, no output schema, and no annotations, the description is critically incomplete. It addresses only one parameter (url) and gives no hint of what happens with the other eight, leaving the agent without enough information to call the tool correctly.

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 input schema provides 100% description coverage for all 9 parameters, so the schema already explains each parameter individually. The description adds no additional semantic meaning beyond the schema, meeting the baseline for schema-covered parameters.

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 ('HTTP status for a public library docs URL') but the tool accepts nine unrelated parameters (city, json, zone, query, etc.), suggesting a multi-purpose checker. It does not clarify that the tool likely performs different checks depending on which parameter is set, making the stated purpose misleading and incomplete.

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 (e.g., fetch-status, browser-url-ok, validate-json, timezone). There is no mention of alternatives or exclusions, leaving the agent to guess the tool's scope.

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