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

The description only mentions that the query is discarded, but does not explain side effects, return values, error conditions, or any other behavioral aspects. Since no annotations are provided, the description carries the full burden and fails to disclose important behavior.

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 unnecessary words. It is appropriately sized for the simplicity of the tool, though it could have been slightly more informative without becoming verbose.

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?

The tool appears to have many irrelevant parameters (e.g., 'city', 'url', 'path') that are not explained in the description. An agent might be confused about whether these are used or ignored. With no output schema and minimal behavioral info, the description is incomplete for safe 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?

The schema description covers all 9 parameters, but the description only references the 'query' parameter. While the schema descriptions are sufficient, the description adds no additional meaning beyond what is already in the schema, so it meets the baseline for high schema 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 clearly states the verb 'Count characters' and the object 'search query', but it does not distinguish the tool from similar sibling tools like 'domain-shape' or 'hn-front-count'. It lacks context on when this tool is needed over others.

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 on when to use this tool versus alternatives. With 27 sibling tools including many shape and length checks, the description provides no criteria for selection, leaving the agent to guess.

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