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

With no annotations, the description carries the full transparency burden. It adds one useful behavioral fact, 'Query discarded', implying the input is not retained, but it does not disclose the return format or how the unrelated schema fields are handled.

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 compact sentences with no filler, and the core purpose is front-loaded. Both sentences earn their place by stating the operation and the disposal behavior.

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?

Despite a nine-parameter schema and no output schema or annotations, the description is minimal. It does not explain the return value, which parameter should be populated, or why the other fields are present, leaving the invocation behavior under-specified.

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 tool description adds no additional parameter-level meaning. The schema's 'query' field description aligns with the tool's purpose, but the description does not clarify the role of the other eight optional parameters.

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 concrete resource, 'a search query', which aligns with the tool name. It does not explicitly differentiate from sibling tools, but the verb+resource pair is enough to convey the core purpose.

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 when-to-use guidance is provided: the description does not mention alternatives, conditions, or which of the nine schema parameters is actually relevant. An agent is left guessing whether to pass 'query' alone or also supply one of the other string fields.

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