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

Annotations already declare readOnlyHint, openWorldHint=false, idempotentHint, and destructiveHint=false. The description adds useful behavior beyond annotations: grapheme-level handling, deterministic output, and operational limits, though it also repeats some annotation-covered safety points.

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 core behavior is front-loaded and the description uses clear labeled sections for when, not-for, side effects, determinism, and limits. It is somewhat longer than necessary because the Spanish and English text duplicate the same information.

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. It still covers the key invocation context an agent needs: grapheme-safe reversal, intended use, exclusion, determinism, side effects, and limits.

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 100%, so the single text parameter is already documented. The description still adds meaning by explaining grapheme-cluster semantics and input/output limits beyond the schema's basic string definition.

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 verb and resource: reversing text by grapheme clusters. It explicitly distinguishes the behavior from case-swap, so an agent can identify the tool without inspecting the schema.

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?

It gives explicit when-to-use guidance (exact transformation, comparison, or measurement rather than approximation) and a clear not-for case (case-swap). The sibling alternative is named directly.

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