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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only mentions that the query is discarded, which is a minor detail. It does not state whether the tool has side effects, requires permissions, has rate limits, or what it returns. For a tool with 9 parameters, this is a significant gap.

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 extremely concise (one sentence), but given the tool's complexity (9 parameters), it is under-specified rather than appropriately concise. It front-loads the primary purpose but lacks any structure or explanation for the non-query inputs, making it insufficient.

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?

Without an output schema, the description should explain return values, but it doesn't. It also fails to reconcile the mismatch between the narrow description and the broad schema, leaving an agent unsure how to invoke the tool correctly beyond passing a query. The tool seems over-engineered for a simple length check, and the description does not address this.

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?

Schema description coverage is 100%, so the baseline is 3, but the description adds no value beyond the schema. It repeats the query discard behavior already in the schema and does not clarify the purpose of the other 8 parameters. An agent cannot determine why url, city, etc., are accepted, or whether they affect the length calculation.

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 lists 9 unrelated optional parameters (url, city, feed, etc.) with no explanation. This makes the tool's actual scope ambiguous; an agent cannot tell if the other fields are ignored, validated, or used for something else. It distinguishes from siblings by focusing on query length, but the schema suggests a broader purpose not reflected in the description.

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 implies a use case (measuring search query length) but provides no explicit guidance on when to use this tool versus alternatives like memory-key-count or hn-front-count, and no exclusions. The context is minimal and leaves selection to inference.

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