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

Beyond the annotations, it discloses the monetary side effect (spending quoted BeautySpark credits), idempotency behavior (re-calling the same quote returns the same job with no extra charge), and the conflict-retry protocol. This is exactly the operational context a mutation tool needs and annotations cannot convey.

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?

Four tight sentences ordered by importance: what it does, what it costs, who calls it, and the two edge-case behaviors. No filler and the cost warning is placed early.

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?

An output schema exists so return values needn't be described, and the description fills in the cost, idempotency, and conflict-handling gaps that neither the annotations nor the schema cover. Nothing needed to call it correctly is missing.

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 baseline is 3, but the description adds real meaning: the quoteId is the idempotency key whose reuse guarantees the same job and no double charge. That goes beyond the schema's bare 'quoteId from try_look_from_photo'.

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 opening sentence gives a specific verb ('Start the try-on') and ties it to the producing sibling ('prepared by try_look_from_photo'), so an agent immediately knows this commits a previously-prepared operation rather than creating one.

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 states exactly when the tool is invoked (the widget's Confirm button), what to do when it isn't (ask the user to confirm cost first), and the retry condition on conflict. The when/when-not/alternative routing is fully explicit.

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