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

Annotations only declare readOnlyHint=false/destructiveHint=false/openWorldHint=false, so the description carries the real behavioral weight: it discloses that no credits are spent, that it produces a fixed quote_id that must be reused verbatim, and that a human confirmation step is required. It does not say whether the quote expires or for how long it stays valid.

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?

Three short sentences with no filler; the no-cost guarantee and the confirmation requirement are front-loaded ahead of the handoff instruction.

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 no output schema, the description usefully names the return value (estimated_credits) and the artifact to carry forward (quote_id), which is what an agent needs to complete the two-step flow. Minor gaps remain around quote validity and the undocumented full_song parameter.

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 must compensate, and the input schema itself has no parameter descriptions. The description implies prerequisites for audio_id ('uploaded audio') and voice_id ('ready owned voice'), adding real constraint meaning, but says nothing about the full_song flag or UUID formats, leaving one of three parameters unexplained.

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 (prepare) and resource (a fixed quote for uploaded audio plus an owned voice), and names the sibling it hands off to (convert_voice). An agent can distinguish this from convert_voice without opening either 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?

Gives an explicit ordered workflow: explain estimated_credits, obtain the user's budget and explicit confirmation, then call convert_voice with this exact quote_id. This is when-to-use, when-not-to-act, and the alternative all in one.

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