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

No annotations are provided, so the description carries the full disclosure burden. It does disclose one useful behavioral fact: 'Query discarded' indicates the input is not retained, which is privacy-relevant. However, it omits other behavioral aspects such as what the tool returns (a number is implied but not stated), whether there are any side effects, and why the other 8 parameters exist if only query is counted.

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?

Two sentences with zero waste. The purpose is front-loaded in the first sentence, and the behavioral note about discarding follows immediately. Every word earns its place.

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?

Given the tool has 9 parameters, no output schema, and no annotations, the description is thin. It doesn't clarify whether the other 8 parameters are relevant to the count, what the return format looks like, or how an agent should pick which parameter to populate. For a tool with this much schema surface area, the minimal two-sentence description leaves gaps, though the 100% schema coverage partially compensates.

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 every parameter is already documented in the input schema, which is the baseline of 3. The description itself adds only marginal parameter meaning ('Query discarded' reinforces the schema's 'discarded after the length check' note) but doesn't explain the relationship between the 9 parameters or which one actually drives the count. The schema already does the heavy lifting.

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 specific verb (count) and resource (characters in a search query), making the core purpose clear. It is distinguishable from count-type siblings like memory-key-count and hn-front-count by the 'search query' resource, though it doesn't explicitly name those alternatives. However, with 9 parameters in the schema, the description only references 'query', leaving the role of the other 8 parameters unexplained at the purpose level.

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 provided on when to use this tool versus the 28 siblings. It doesn't state any exclusions, prerequisites, or conditions that would route an agent here instead of to similar counting tools like memory-key-count or hn-front-count. The agent must infer usage solely from the name and short description.

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