word_stats

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

Annotations already declare this as a safe read-only, closed-world operation. The description adds useful behavioral detail beyond that: frequency ranking is case-insensitive and character counting is Unicode-aware.

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 definition is a single well-structured sentence with no wasted words and the core capabilities are 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?

For a simple read-only utility with complete schema descriptions, annotations, and an output schema, the description provides enough context for correct invocation. No critical behavioral or parameter information is missing.

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?

Both parameters are fully documented in the schema, including the 'text' size limit and 'top' default/range. The description does not add parameter-level meaning beyond the schema, which is acceptable at 100% schema coverage.

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 specific operations: counting words, counting Unicode characters, and ranking words by frequency. This is a clear verb+resource statement, and the utility is readily distinguishable from the unrelated sibling 'add'.

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 explains what the tool does but gives no guidance on when to use it versus alternatives, prerequisites, or exclusions. The only sibling is unrelated, but no usage context is still provided.

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