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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true), and the description adds real behavioral value: it spends credits, returns video ids immediately rather than blocking, and requires polling get_video. It does not reconcile 'spends credits' with idempotentHint=true (retry/double-charge safety), which is the main remaining gap.

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 short sentences, cost and quote dependency front-loaded, no filler. The final sentence about uploading in Spotify for Artists earns its place as downstream context, though the clipped grammar across sentences makes it read as notes rather than a polished definition.

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 compensates well by stating what comes back (video ids) and how to follow up (poll get_video), plus the credit cost and quote prerequisite. It omits failure/cancel behavior and retry semantics despite the idempotentHint, but is otherwise sufficient to invoke correctly.

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 description coverage is 100% across 12 parameters with 5 enums, so the schema already carries the parameter burden; baseline is 3. The description only restates the quote_id/request-identity constraint already spelled out in the schema, adding no new semantics for fields like direction, variations, or callback_url.

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 and resource (make/create the Canvas) and, crucially, distinguishes itself from the sibling quote_canvas by noting it takes the quote's request 'plus its quote_id' and spends credits. The phrasing is grammatically awkward ('Make the Canvas a quote priced'), which slightly blurs the action, but the intent is recoverable.

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?

Encodes the workflow: reuse the quote request plus quote_id, then poll the named sibling get_video until status is completed, then upload the file in Spotify for Artists. It gives a clear precondition and a follow-on path, though it never explicitly says 'call quote_canvas first' or when not to use this tool.

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