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

The description discloses that the query is discarded after the length check, which is useful side-effect information. However, it does not clarify that the many other schema parameters appear irrelevant or are ignored.

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 very concise, using two short sentences that each add value. It states the action and an important side effect without unnecessary elaboration.

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 format, the counting unit (e.g., characters vs. bytes), or clarify the role of the other 8 schema parameters. Given the absence of an output schema, this leaves important details ambiguous.

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 every parameter has a schema description, most descriptions appear copied from unrelated tools and do not align with a simple 'count characters in a query' function. The top-level description does not explicitly state that only the 'query' parameter should be used, creating potential confusion.

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's primary function: counting characters in a search query. It is specific enough to distinguish the intended resource, though it does not explicitly contrast with any sibling tool.

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 use case is implied by the description—when a search query's length is needed—but there is no explicit guidance about when to use this tool versus alternatives. No when-not-to-use conditions are stated.

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