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 mentions that the query is discarded, which is useful, but it does not clarify whether the operation is purely local, what side effects exist, or what the tool returns. The 'discarded' detail is also already present in the schema.

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 and front-loaded: it states the action first and the data-handling note second. It contains no fluff, though it is terse enough that some completeness is sacrificed.

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?

With nine optional parameters, no annotations, and no output schema, the description is too sparse to fully guide invocation. It does not specify the return format, which parameter to use, or how to handle the extra fields, leaving the agent to rely heavily on schema inference.

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 each parameter is already documented. The description adds the notion of counting characters but does not clarify which of the nine optional parameters is the intended 'query' input beyond inference from the tool name and the query parameter description.

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 a specific action: counting characters in a search query. It aligns with the tool name and identifies the core behavior, though it does not contrast with sibling length-related tools.

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?

There is no guidance on when to use this tool, what distinguishes it from alternatives like memory-key-count or hn-front-count, or what prerequisites apply. The description only states the operation without usage context.

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