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

There are no annotations, so the description carries the full burden. It does disclose that the query is discarded, which is useful data-handling context, and 'count' implies a read-only operation. However, it does not state the return format, whether other parameters are ignored, or edge-case behavior such as empty input.

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 two short, front-loaded sentences with no filler. Every sentence adds information: the operation and the data-discard behavior. For a tool this size, this is appropriately concise.

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 is only one line. It does not explain what the tool returns, which parameter is the intended search query, how to handle multiple provided parameters, or what happens when none are provided. This is incomplete for the level of ambiguity in 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 query parameter is clearly described as 'Search text; discarded after the length check,' which aligns with the tool description. The description adds no further parameter-level meaning, and the 8 other unrelated-looking optional parameters create ambiguity that is left unresolved.

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 concrete operation: count characters in a search query. It names a clear verb and resource, and the second sentence clarifies that the query is not retained. However, it does not differentiate this from sibling counting tools like memory-key-count or hn-front-count, so it stops short of a 5.

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 only implies a narrow use case: needing the character length of a search query. It gives no explicit guidance on when to use this tool versus alternatives, no exclusions, and no indication of which of the 9 optional parameters should be provided. This is minimal guidance at best.

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