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

With no annotations provided, the description carries the full burden. It discloses that the query is discarded, which is a useful side-effect guarantee (no retention). However, it does not mention what happens to the other optional parameters, any limits, or the nature of the return value, leaving most behavioral traits unstated.

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 with zero filler. The primary purpose is front-loaded ('Count characters in a search query') and the secondary behavioral note ('Query discarded') is brief and essential. No words are wasted.

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 plus the schema are just sufficient for an agent to invoke the tool correctly: the 'query' parameter is explicitly tied to the length check. However, the description does not explain why eight other optional parameters exist, what the return value looks like, or how to handle multiple provided parameters, leaving notable ambiguity for an agent navigating the tool set.

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 input schema already thoroughly documents all nine parameters. The description adds no parameter-level detail beyond what the schema provides; it only aligns with the 'query' parameter by mentioning 'search query'. This matches the baseline of 3 for high schema 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 states a specific action (count characters) on a specific resource (a search query), and 'Query discarded' adds a clear scoping detail. It does not, however, distinguish itself from sibling tools that also measure counts, nor does it explain why the schema includes eight other unrelated parameters, so it falls 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?

There is no guidance on when to use this tool versus alternatives. It does not mention conditions, prerequisites, exclusions, or any relationship to the many sibling tools. The only contextual hint comes from the schema's 'query' parameter description, not from the tool description itself.

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