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

No annotations are provided, and the description only notes that the query is discarded. It does not disclose whether the tool performs validation, what side effects (if any) occur, or what the returned response contains.

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 a single clear sentence with no fluff, making it easy to parse. It sacrifices some useful detail, but it is appropriately sized for a simple counting operation.

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?

The description is too sparse for the actual schema: it does not explain why eight unrelated parameters exist, what the output format is, or how to choose among optional inputs. This leaves an agent uncertain about a correct invocation.

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?

Although the schema has descriptions, most are unrelated to the stated purpose (e.g., 'Git ref name', 'HTTPS URL to normalize or cite', 'City name for a public weather hint'). Only 'query' aligns with the tool's purpose, so the parameter meanings are misleading rather than helpful.

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 'Count characters in a search query' uses a specific verb and resource, making the core action clear. However, the schema exposes many unrelated optional parameters (ref, url, city, feed, host, json, path, zone) that muddy which resource is actually being operated on.

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 the many sibling validation/check tools. It does not state that it is for measuring query length only, nor does it mention any alternatives or preconditions.

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