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

With no annotations, the description carries full responsibility for behavioral disclosure. It does disclose that the query is discarded, but it fails to explain the behavior of the other 8 parameters (are they used or ignored?) and does not mention the return format or side effects. The schema hints at each parameter's fate, but the tool description itself is minimal.

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 concise sentence, which is front-loaded with the purpose. However, it is under-specified for a tool with 9 parameters; conciseness should not sacrifice essential context. It earns a 3 – it is not bloated but it is too sparse to be fully effective.

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?

Given the complexity of 9 optional parameters, no output schema, and no annotations, the description is incomplete. It only addresses the 'query' parameter and does not explain what happens with the others, what the return value is, or any error conditions. An agent calling this tool would lack critical information.

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% – every parameter is documented in the schema. The tool description adds no extra meaning beyond the schema; it only repeats the idea of discarding the query, which is already in the parameter description. Baseline is 3 because the schema does the heavy lifting.

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 verb and resource: 'Count characters in a search query.' This is specific and not a tautology. However, it does not differentiate from sibling count-like tools such as 'memory-key-count' or 'hn-front-count', so it loses a point for lacking sibling distinction.

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 gives no guidance on when to use this tool vs. alternatives. It does not mention any conditions, exclusions, or sibling tools. The only clue is the name 'search-query-len', but the description itself provides no usage context.

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