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

Goes well beyond the annotations (destructive/openWorld/non-idempotent) by disclosing the credit cost range (~50–200, dynamic, returned as creditsReserved), the async jobId/poll lifecycle, automatic credit refund on failure, and the 'auto' actor-pick side effect plus the characterId/actorPick response fields for campaign persistence. This is the mutation-cost and side-effect detail an agent needs before spending credits.

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 async+credit warning, then the UGC requirement, then the follow-up action. Dense parentheticals are all load-bearing (cost range, allowed UGC types, actorPick fields) rather than filler.

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 still covers the return contract (jobId, creditsReserved, characterId + actorPick) and the async polling path. Combined with the rich behavioral caveats, an agent has everything needed to invoke and then follow through.

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 63%, and the description compensates on the highest-risk params: videoType's UGC subset, characterId semantics ('auto', saved actor, persistence), and duration→credit mapping. It adds little on platform enum, scenePrompt, or additionalInstructions, so it is strong but not exhaustive.

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?

Opens with a specific verb+resource+mode: 'Kick off an ASYNC full video production job (the Quick Create flow)'. It names the flow variant, which separates it from sibling generators like create_ai_story, create_ai_edit and studio_generate_video, so an agent can route 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?

Explicit conditional routing: UGC video types ('ugc','brainrot','ugc-broll','ugc-demo') REQUIRE a script and characterId, with the alternative sources named (list_characters / list_character_library) and 'auto' described as the fallback. It also states the follow-up step (poll get_job until completed).

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