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

The phrase 'Query discarded' discloses a useful behavioral trait: the input is not retained after the call. Since no annotations are provided, the description carries the burden, but it omits other behavioral details such as the returned value or whether only certain property types are accepted.

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 the core action stated first and the side-effect noted second. It is efficient and easy to parse, though the missing parameter linkage prevents it from being fully useful.

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 nine schema properties, no output schema, and no annotations, the description must do much more work. It fails to explain what the tool returns, which parameter represents the query, or how this tool relates to the many sibling tools, leaving the agent with a significant gap.

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 descriptions are fairly complete for each property, giving the description a high baseline. However, the description introduces a 'search query' concept that does not appear in the schema, and it provides no mapping from any parameter to that concept, leaving the agent unable to determine which string should be counted.

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 names a specific action ('Count characters') and a clear object ('a search query'), so the basic purpose is understandable. However, it never connects 'search query' to any of the nine input properties—the schema contains no 'query' field—so an agent cannot tell what operand this tool actually consumes.

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, when not to use it, or what sibling alternatives might be more appropriate. 'Query discarded' implies a one-shot, non-persistent check, but the description does not state the intended context or selection criteria.

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