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

With no annotations, the description carries the behavioral burden. It discloses that the query is discarded, which is useful transparency, and implies a read-only operation. However, it does not describe the return value format or any error behavior, which would strengthen the description. For a simple counting tool, this is adequate but not comprehensive.

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 waste. The key operation is stated upfront, and the discard behavior is a meaningful addition. It is appropriately sized for the tool's simplicity.

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?

With 9 optional parameters and no output schema, the description is incomplete. It does not specify which parameter(s) to pass, what the tool returns, or how multiple inputs are handled. An agent would need more details to reliably invoke this tool correctly, especially given the wide parameter variety.

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. However, the description only references 'search query', which presumably maps to the 'query' parameter, but the tool has 8 other parameters with no explanation of how they relate. The description does not clarify whether the tool counts characters in any provided string or only the 'query' parameter, and the mention of 'search query' is ambiguous given the broad set of string parameters. Thus it falls below the 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 clearly states the verb 'count' and the resource 'search query', making the purpose specific. However, it does not differentiate from sibling tools like memory-key-count or hn-front-count, which also count things, so it loses the full mark for sibling differentiation.

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?

There is no guidance on when to use this tool versus alternatives. The description does not mention any context, prerequisites, or exclusions, leaving the agent to infer usage from the name alone.

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