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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does disclose one trait: 'Query discarded,' which suggests the query is not persisted. But it does not clarify whether the other eight parameters are ignored, whether any network call occurs, what the return value is, or whether the tool has side effects.

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 short and front-loaded with the action: 'Count characters in a search query.' The second sentence is a meaningful behavioral note, not filler. It is concise, though it sacrifices information that is needed elsewhere.

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?

For a tool with nine optional parameters, no required parameters, no annotations, and no output schema, the description is incomplete. It does not state which parameter to populate, that other parameters are ignored, or what the tool returns. An agent cannot reliably know how to invoke it correctly beyond guessing that query is relevant.

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?

Schema description coverage is 100%, so the structured schema already documents each parameter, including 'Search text; discarded after the length check' for query. The description adds little beyond naming 'a search query' and does not clarify that query appears to be the only relevant parameter among the nine optional fields, but the high schema coverage keeps this at baseline.

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 uses a specific verb and resource: 'Count characters in a search query.' This clearly states the core action and distinguishes it from a mere tautology. However, it does not differentiate the tool from siblings such as memory-key-count or normalize-url, so it stops short of a 5.

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 about when to use this tool versus alternatives. The description does not mention any sibling, exclusion condition, or preferred context, leaving the agent to infer usage entirely from the name and schema.

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