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

The description discloses that the tool is free, AI-generated, and rate-limited, which are behavioral traits not covered by the readOnlyHint annotation. It adds meaningful constraints for the agent, though it does not detail rate limits or input size limits.

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 a single, front-loaded sentence with a parenthetical for extra context. Every word earns its place, and there is no fluff.

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 2-parameter tool with no output schema, the description covers the core action and key constraints, but it does not state what the tool returns or any limitations on input length. The agent would know to send text and an optional tone, but not what to expect in response.

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 description contributes some context for the 'text' parameter by indicating it is the source text to be rephrased, but it does not explain the 'tone' parameter beyond the schema's minimal description. With 50% schema coverage, the description only partially compensates.

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 clearly states the tool's function with a specific verb ('Rephrase') and resource ('text'). It distinguishes from siblings like article-summarizer, which condenses rather than rephrases.

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 description provides no explicit guidance on when to use this tool over alternatives. It does not mention any exclusions or alternative tools (e.g., article-summarizer for summarizing). Usage is only implied by the verb, but no clear context is given.

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