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

Annotations declare the safety profile (readOnlyHint=false, idempotentHint=false, openWorldHint=true, destructiveHint=false), so the description's added value is the payment disclosure: $0.002 USDC on Base per successful call via x402. That auth/cost detail is genuinely non-obvious and material before invoking. It omits rate limits or whether input text is retained.

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?

Two sentences, front-loaded with the core action and styles before the usage and cost details. The style enumeration is somewhat redundant with the enum but is compact and reads naturally.

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 two-parameter text tool with no output schema, the description covers action, styles, use cases and cost, which is close to sufficient. It never indicates what is returned (rewritten text only?) or whether the original is preserved, leaving a small gap that an output schema would otherwise fill.

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% and both parameters are documented in the schema, including the default of 'professional'. The description merely re-lists the same style values as the enum, adding no syntax, length, or interaction guidance beyond structured data.

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?

States a specific verb (rewrite) plus the full set of target styles, and the phrase 'keeping the meaning and language' implicitly separates it from siblings like ai_summarize-text or ai_translate. It is clear on its own, though it never names an alternative tool explicitly.

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?

Gives concrete usage contexts ('polish emails, replies, product copy and messages'), which tells the agent when this tool fits. It stops short of exclusions or naming when to prefer a sibling (e.g., ai_summarize-text for shortening).

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