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

The description discloses that the query is discarded and that the path parameter involves no disk access, but it does not explain potential side effects or interactions for the other accepted parameters.

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 with no redundant elaboration.

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?

There is no output schema or statement of the return format (e.g., integer length, including/excluding whitespace), and the role of each optional parameter is not explained, so callers cannot confidently determine correct usage.

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?

Although every parameter has a description, most of the parameters (ref, url, city, feed, host, json, path, zone) appear unrelated to counting query characters and are not marked as ignored, creating confusion about what to pass.

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 clearly states the action ('Count characters') and the target ('a search query'), making the core purpose understandable despite the odd additional parameters.

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 given on when to use this tool versus sibling tools, and the nine optional parameters with no required fields leave it unclear which input is actually needed.

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