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

With no annotations, the description must fully disclose behavior. It only says 'Query discarded', which implies read-only and stateless, but it omits any details about the return format, error handling, or that other parameters are ignored. This is minimal and leaves the agent guessing about side effects or output semantics.

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 short sentences with no filler. The key action ('Count characters') and the fact that the query is discarded are front-loaded, making it easy to scan. No redundant content.

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 there is no output schema, the description must explain what the tool returns. It does not state whether it returns the length, a boolean success, or something else. It also fails to mention that only the 'query' parameter matters, which is essential for correct invocation with 9 optional parameters. This is a significant gap for an agent to use it properly.

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 extra meaning to the 9 parameters; it only implicitly references the 'query' parameter via 'search query'. It does not clarify that the other 8 parameters are irrelevant, which could mislead an agent into thinking they affect the result.

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 action ('Count characters') and a resource ('search query'), making the core purpose clear. However, it does not explicitly differentiate from sibling shape-check tools (e.g., domain-shape, file-path-ok) by naming an alternative, and it leaves the return value ambiguous (just a count? a boolean?).

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 on when to use this tool versus the many sibling shape-check tools. It does not state that this is specifically for query length validation, nor does it mention any prerequisites or exclusions. An agent would have to infer its scope 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.