char_count

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

No annotations provided, so description carries full burden. It ambiguously states 'including/excluding spaces and non-printable chars' without specifying which behavior is default or how to control it. No disclosure of how the tool handles edge cases or what the output format is.

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?

Description is concise (two lines) and front-loaded with the core functionality. The parameter list is structured. However, the ambiguous phrase about including/excluding could be clarified without adding much length.

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 an output schema present, the description does not need to explain return values. However, the lack of clarity on the include/exclude behavior and no mention of error handling or edge cases leaves gaps. Given the tool's simplicity, it is minimally adequate.

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 coverage is 0%, so the description adds value by explaining the 'text' parameter as 'Text to analyze character count.' This clarifies the parameter's purpose beyond the schema's simple type declaration. For a single parameter, this is sufficient.

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?

Description clearly states the tool counts characters in provided text. Verb 'Count' and resource 'characters' are specific. However, it does not differentiate from sibling tools like word_count or line_count, and the mention of including/excluding spaces and non-printable chars is misleading because no such parameters exist.

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 on when to use this tool versus alternatives. Does not mention preferred contexts or exclusions. Sibling tools perform similar tasks, but no comparative information is provided.

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