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

Beyond the readOnly/idempotent annotations, it discloses the 25-second long-poll wait, the three terminal/intermediate states, that 'done' yields hosted media-library URLs plus a suggested caption, and that 'failed' produces nothing and refunds credits. This is exactly the mutation-adjacent behavior (credit refunds, output artifacts) an agent needs.

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?

Front-loaded with the action and the polling rule, then branches cleanly by status. Slightly long, with the retry instruction restated ('no need to wait between calls' / 'call it again'), but every sentence carries actionable information.

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 an output schema and rich annotations already present, the description fills the remaining gaps: polling cadence, per-status meaning, and credit-refund behavior. Nothing an agent needs to poll and interpret results 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% and the single parameter's schema description already says it is the generationId returned by studio_generate, which the description largely repeats. No additional format, validation, or lifetime details are added, so the baseline 3 applies.

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 ('Check a generation started with studio_generate') and ties it to the sibling that produces the generationId. An agent can distinguish this from studio_generate, studio_formats, and videoStatusTool without opening any 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?

Explicitly says when to call again ('status is "queued" or "running" call it again'), how to pace it (25-second long-poll, so no need to wait between calls), and what to tell the user after a few calls. It also implicitly excludes use before studio_generate by requiring its generationId.

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