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

The annotations already establish that this is read-only, idempotent, and non-destructive. The description adds useful behavioral context by disclosing the 1-credit cost and clarifying the returned value, though it does not discuss edge cases or error behavior.

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 front-loaded and very short: one clear sentence plus a parenthetical cost note. Every part earns its place, and the return semantics are clarified without unnecessary wording.

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?

For a simple one-parameter pure utility with full schema coverage and rich annotations, the description supplies the operation, the result, and the cost. No output schema is needed because the return value is explicitly stated.

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 single text parameter is fully documented in the schema as required text to reverse. The description adds no syntax, format, or constraint details beyond what the schema already provides, so the baseline score for 100% schema coverage is appropriate.

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 precise verb and resource: it reverses the order of characters in a given string. It also states the return result, so the operation is unambiguous and distinguishable from sibling utilities.

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?

The use case is implied by the operation itself: call it when a string needs to be reversed. However, there is no explicit when-to-use or when-not guidance, nor any comparison to related sibling tools such as text_stats or is_palindrome.

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