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

The description discloses that the query is discarded, but it does not mention return format, edge cases, errors, or any side effects. With no annotations, this leaves important behavior unspecified.

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 concise and front-loaded; both sentences earn their place by stating the purpose and the disposal behavior.

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 description is incomplete for a tool with nine parameters and no output schema. It does not explain return values, which parameters are necessary, or how to handle the extraneous fields.

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 descriptions are unrelated to counting characters (e.g., 'HTTPS URL to normalize or cite', 'IANA timezone name'). The description does not clarify that only 'query' is relevant, making the parameter list misleading.

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 tool's function: counting characters in a search query, and explicitly notes the query is discarded. The verb and object are specific enough to distinguish it from other 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?

The description implies when to use the tool (when a character count of a search query is needed), but it does not provide explicit guidance or contrast with sibling tools.

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