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

The phrase 'Query discarded' implies the tool has no side effects on the input, but it does not explicitly state read-only behavior or side effects for other accepted parameters. Given no annotations are provided, the description carries the burden and only partially addresses it.

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, short sentence that efficiently conveys the core action. However, it omits needed clarification about parameter usage, so it is not perfectly complete.

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 lacks an output schema and any description of the return value format. Combined with the misleading parameter descriptions, the agent cannot reliably know what the tool returns or which inputs are actually required, so the context is incomplete.

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 lists 9 optional parameters with descriptions that are clearly copy-pasted from unrelated tools (e.g., 'Git ref name', 'City name for a public weather hint'). Only 'query' logically matters for the stated purpose, but the description does not clarify that the other parameters are ignored, leading to significant ambiguity.

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 counts characters in a search query, which is a specific action on a specific resource. It distinguishes it from sibling length/count tools by focusing on search queries, though it doesn't name related 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?

No guidance is given on when to use this tool versus alternatives like other length-checking tools. The description only mentions the operation, leaving the decision context entirely to the agent.

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