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

The description explicitly states that the query is discarded, and the schema descriptions for other parameters also mention they are discarded after checks. This makes the side effects transparent even without annotations, though the full behavior for all parameters is not consolidated in the tool description.

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?

Extremely concise with only two short sentences. No superfluous wording, and the core function is communicated directly.

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 does not specify the return value or output format (e.g., whether it returns a number or a string), and it does not explain how the extra schema parameters fit into the operation. Given the tool's simplicity, these omissions make the description incomplete for confident use.

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 tool description adds minimal meaning beyond the schema; it only reinforces that the query is counted. The schema contains many extraneous parameters that are not explained in the description, causing confusion about their purpose or why they exist in a query-length tool. The description does not clarify that only 'query' is relevant.

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 clearly states the tool counts characters in a search query and discards it, giving a specific verb and resource. However, the presence of many seemingly irrelevant parameters in the schema creates some ambiguity about the actual scope, so it is not a perfect 5.

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 indication of when to use this tool versus alternatives like other sibling count tools. The description lacks any contextual guidance for selection, leaving the agent to infer applicability solely from the name and brief text.

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