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

With no annotations, the description at least discloses that the input is discarded after use, indicating a non-persistent operation. However, it does not describe the return value, error behavior, or how invalid inputs are handled, so the behavioral disclosure is only partial.

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 only two short sentences with no filler. The action and side-effect statement are front-loaded, though the missing mapping to inputs prevents a perfect conciseness score.

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 seven parameters, no annotations, and no output schema, the definition is incomplete: it fails to specify which parameter carries the query, what the returned count represents, and what happens on invalid input. An agent cannot confidently invoke this tool from the description alone.

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?

The schema descriptions cover all seven parameters, so the baseline is 3, but the tool description itself adds no parameter-level meaning. It references a 'search query' that does not map to any of the schema properties, which actively confuses parameter selection.

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 clear action, counting characters in a search query, but the input schema exposes seven unrelated parameters (ref, url, city, feed, host, json, path) with no 'query' property. It does not tie the action to any of the actual inputs, and there is no differentiation from sibling shape-check tools. This is closer to misleading than to a usable purpose statement.

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 for when to use this tool instead of a sibling such as validate-json, normalize-url, or web-fetch. The single sentence neither states conditions nor exclusions, leaving the agent to guess which input is a 'search query'.

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