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

With no annotations, the description carries the full burden of behavioral disclosure. It does disclose that the query is discarded, which is a useful privacy-relevant behavior. However, it does not mention return format, error behavior, or what happens if multiple parameters are supplied, so transparency 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 two short sentences with no filler, and the core action is front-loaded. Every word earns its place, and there is no redundant information.

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 tool has seven optional parameters, no output schema, and no annotations, yet the description only covers counting and discarding. An agent cannot determine the return value, which parameter to pass, or when to prefer this tool over its siblings, so the definition is not complete enough for reliable 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?

The schema has descriptions for all seven parameters, which normally earns a baseline of 3, but none of the properties (ref, url, city, feed, host, json, path) maps to a 'search query' and the description gives no clue which parameter to use. The property descriptions appear to belong to unrelated tools, so the definition fails to help an agent select the correct input.

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 names a specific verb ('Count') and resource ('characters in a search query'), so the core action is clear. However, it is vague about what counts as the 'search query', and the input schema exposes seven unrelated parameters with no 'query' field, which undermines the clarity. It also does not differentiate this tool from any sibling.

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 provides no guidance on when to use this tool versus alternatives, no exclusions, and no context about prerequisites or typical use cases. It only states what the tool does, leaving the agent to infer when it is appropriate.

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