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

With no annotations present, the description carries the full burden of behavioral disclosure. It clearly states that the query is discarded, which conveys that the operation is effectively stateless and does not persist user-provided search text. It does not specify return details or character-count semantics, but for a simple read-only utility the main privacy-sensitive behavior is disclosed.

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: two short sentences, both of which earn their place. It front-loads the core action and then states the key behavioral detail. There is no filler or repetition.

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 is too thin for a tool with nine optional parameters, no annotations, and no output schema. It never explains that 'query' is the intended input field, what happens if multiple fields are supplied, or what the tool returns beyond the implied character count. The agent is left to infer critical invocation details from the schema.

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. The description adds little beyond the schema: 'Query discarded' echoes the query parameter's own description. It also does not clarify that, among the nine optional parameters, only 'query' is relevant to this tool.

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 verb and resource: 'Count characters in a search query.' It also adds the discard behavior, which helps distinguish this from related validation tools. However, it does not explicitly differentiate it from siblings like memory-key-count or hn-front-count.

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 versus alternatives, and it names no sibling tools or exclusion criteria. It only implies usage through the phrase 'search query,' but an agent is not told when to prefer this over other length or validation tools.

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