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

With no annotations present, the description carries the behavioral burden. 'Query discarded' appropriately discloses that the query text is not retained after the call, which is useful. However, it does nothing to disclose how the other 8 parameters are handled, whether multiple inputs cause an error, or whether the output is simply an integer; the transparency is only partial.

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 sentences, front-loaded with the primary action and immediately adding the most important side-effect note. It contains no filler or redundancy, making it appropriately concise for the simple function name.

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, but the description only says 'Count characters in a search query. Query discarded.' It doesn't clarify how to choose among the many string fields, whether multiple can be passed, how the result is returned, or why the other parameters are present. For an agent to use this tool correctly, this gap is significant.

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 describes each parameter. The description adds almost nothing beyond picking out 'search query' and noting it is discarded. It does not clarify which of the exposed fields is actually counted, nor whether the others are ignored, leaving a semantic gap despite the high coverage.

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 action: count characters in a search query, with 'Query discarded' giving additional scope. However, it does not explicitly differentiate from sibling counting tools like hn-front-count or memory-key-count, though the underlying purpose is understandable.

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 versus any alternative, nor any mention of when not to use it. The tool schema exposes 9 optional parameters, but the description does not specify which parameter (query only?) is intended, let alone how it relates to other tools with similar shape or count behavior.

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