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

There are no annotations, so the description carries the burden of behavioral disclosure. 'Query discarded' usefully signals that the input is not persisted and that the operation is effectively stateless. However, it does not describe output format, error behavior, or whether non-query fields are ignored, leaving some behavioral ambiguity.

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 two short sentences with no fluff: it states the core action first and then the key non-retention behavior. Every word earns its place, and the structure is front-loaded.

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 has a generic nine-parameter schema with no required fields and no output schema, so the description could do more to clarify that only the `query` field is relevant and to state the return value explicitly. The existing text plus the schema's `query` description is likely enough for a simple length check, but it is not fully complete for an agent facing many optional parameters.

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 schema already documents each parameter, including `query` as 'Search text; discarded after the length check.' The description itself adds no parameter-level meaning beyond confirming that the query is discarded. Baseline 3 is appropriate because the schema carries the parameter documentation load.

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 action ('Count characters') and the target ('a search query'), which distinguishes it from most sibling validators and counters. It does not explicitly name the `query` parameter or say the result is the character count, but the intent is recognizable from name + description.

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 instead of alternatives such as `memory-key-count`, `hn-front-count`, or the shape-checking siblings. The description implies its use for measuring search-query text, but it never states conditions, exclusions, or alternative tools.

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