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

The description mentions that the query is discarded, hinting that no persistent storage occurs, but does not explain that other parameters are ignored or what the return value is. With no annotations provided, more behavioral detail would be expected.

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 free of unnecessary words, which fits a simple utility. The two-sentence structure is straightforward, though it omits critical context about parameter usage.

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?

Given the presence of 9 parameters and a single-focused purpose, the description is incomplete. It does not clarify that all parameters except 'query' are irrelevant, nor does it describe the output format or behavior when 'query' is absent. This leaves the agent to figure out the intended usage from the schema alone.

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 descriptions cover all 9 parameters, including a clear description for the 'query' parameter as 'Search text; discarded after the length check.' However, the description does not add any extra meaning beyond the schema, such as emphasizing that only 'query' is significant, leaving the purpose of other fields unclear.

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 primary action: counting characters in a search query. The phrase 'Query discarded' is slightly ambiguous but does not obscure the core purpose. The tool name reinforces the intent.

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 gives no indication of when to use this tool versus any alternative. It does not mention which parameters are relevant or that only 'query' is used, leaving the agent to infer from the schema.

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