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

No annotations are present, so the description carries the burden. It does disclose that the query is discarded after use, which is a meaningful behavioral note. However, it does not say what happens with the other eight accepted parameters, whether an empty or missing query is valid, or what the tool returns.

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, front-loaded with the main action, and 'Query discarded' earns its place as a data-handling note. It is slightly too terse to be a 5 because it omits a pointer to the actual input field.

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?

With 9 optional parameters, no annotations, and no output schema, the definition underdetermines correct invocation. It never states that the `query` parameter is the one to populate or what happens to the unrelated parameters, so an agent must infer critical call 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 no parameter-level information; the schema's per-parameter descriptions carry that load. The many unrelated optional fields still create ambiguity about which parameter is the intended 'query'.

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 operation ('Count characters') on a specific resource ('a search query'), and the name plus note about discarding make it distinct from sibling count/validation tools. It is not a restatement of the name and has a clear outcome.

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 about when to use this tool versus alternatives, no prerequisites, and no mention of when not to use it. The only usage signal is the implied purpose of counting query characters.

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