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

The description mentions 'Query discarded,' which discloses one side effect. But it is silent on the behavior with the other parameters, the output format, and any potential side effects. With no annotations, the description carries the full burden and fails to meet it.

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 concise, consisting of two short sentences, but it is under-specified. It lacks critical information about scope and behavior, so while it is efficient in length, it is not appropriately structured for the tool's complexity.

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 parameters, no output schema, and no annotations. The description is critically insufficient: it does not explain how to handle the other parameters, what the return value is, or when to prefer this tool over siblings. An agent cannot call it correctly with this information.

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?

The schema already describes each parameter, so baseline is 3. However, the description's exclusive focus on 'query' could mislead an agent into thinking only that parameter matters, while the schema includes many other fields. This adds confusion rather than value, lowering the score.

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 clear action: 'Count characters in a search query.' However, it does not acknowledge the other eight parameters in the schema, creating ambiguity about the tool's full scope. It is distinguishable from sibling shape-check tools only by implication, not explicitly.

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?

No guidance is provided on when to use this tool versus alternatives. The description does not mention any conditions, scenarios, or exclusions, leaving the agent to infer usage entirely from the schema.

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