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

There are no annotations, so the description carries the full burden. It does disclose that the query is discarded, implying no persistence or real search behavior, and 'count characters' suggests a pure read-only operation. However, it does not clarify behavior for the other eight schema parameters or mention any error conditions.

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 concise: two short sentences with the main purpose front-loaded. The second sentence 'Query discarded' adds meaningful behavioral information without waste. It is slightly under-specified, but not padded.

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?

Despite 100% schema coverage, the tool has nine optional string parameters with no output schema and no annotations. The description does not clarify that only 'query' is relevant, what happens with the other parameters, or the return format. This ambiguity makes the definition incomplete for confident invocation.

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 baseline is 3. The description adds no parameter-level meaning beyond the schema; it only mentions 'a search query' while the schema already describes the query parameter in detail. This is adequate but not additive.

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 states a clear operation: 'Count characters in a search query.' This is a specific verb plus resource. It does not explicitly contrast with siblings like memory-key-count or hn-front-count, so it misses full sibling differentiation, but the core purpose is unambiguous.

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 guidance about when to use this tool versus alternatives, nor does it mention when not to use it. It only states the operation, leaving the agent to infer appropriate usage from the tool name and schema.

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