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

With no annotations provided, the description carries the full transparency burden. 'No identifiers are retained' is a useful privacy disclosure, but the description does not state whether the tool is read-only, whether it makes external calls, what side effects occur, or what the response looks like.

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 very short and has no wasted words, with a clear two-sentence structure. However, the extreme brevity leads to under-specification: it is concise more because it says almost nothing than because it efficiently conveys the necessary information.

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 tool has 9 optional parameters, no output schema, and no annotations, so the description needs to explain how to invoke it correctly. It does not say whether exactly one parameter should be provided, what the classification output is, or how this tool relates to its sibling tools. An agent would struggle to use it 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?

Schema description coverage is 100%, and each parameter has a terse but meaningful description (e.g., 'discarded after the check' or 'for a public weather hint'). The tool description itself adds no parameter-level meaning, but the schema already covers that ground.

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 gives a verb and a subject: 'Show how this request is classified.' However, it never explains what 'classified' means, what classifications exist, or how the tool relates to its name 'compatibility.' It also does not distinguish this tool from the many sibling shape-checking and URL-checking 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?

There is no guidance about when to use this tool versus alternatives such as validate-json, normalize-url, domain-shape, or file-path-ok. The description provides no conditions, exclusions, or hints about which input should be provided.

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