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

With no annotations, the description needs to disclose behavioral traits, and 'Query discarded' usefully indicates the input is not retained. However, it does not clarify the return value, behavior on empty input, or why several other parameters exist.

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?

Two short sentences with no filler. The core operation is stated first, and the disposal note is a valuable second sentence.

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 tool has 9 optional parameters, no annotations, and no output schema, yet the description does not explain that only 'query' is used or what happens with the other fields. An agent could be uncertain about what to pass and what to expect back.

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 schema already documents every parameter. The description reinforces that the search query is the relevant input but adds no meaningful information beyond the schema.

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 operation and resource: count characters in a search query. It is distinct from sibling tools like memory-key-count or hn-front-count by focusing on query length, though it does not explicitly compare itself to any alternative.

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 usage guidance is provided. The description does not state when to choose this tool over other counting/shape-check tools, nor does it mention any exclusions or prerequisites.

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