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

Goes well beyond the annotations: discloses ASYNC execution, that a jobId is returned, that get_job must be polled, that per-slide assets come via get_video, and that it spends ~20 credits. It does not explain what the destructiveHint implies operationally, but the async/cost/polling detail is strong added value.

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 dense sentences with zero filler, front-loading what it produces before the operational details. Every clause earns its place, including the cost and polling instructions.

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 carries the return-path burden and does so (jobId → get_job → get_video). For a 4-param, credit-spending generation tool the async flow, cost, and input prerequisite are covered; only the platform/name params are left to the schema.

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 50% and the schema already documents prompt and referenceImageUrl. The description reinforces the reference-image requirement ('public referenceImageUrl', 'single reference image') but adds nothing for name or platform, so it stays at baseline.

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 (generate), a precise resource (portrait 5-slide deck), and a scoping constraint (varied from a single reference image). This is distinguishable from siblings like create_video and studio_generate_image 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?

Gives clear prerequisites (requires a public referenceImageUrl) and cost guidance, but never names an alternative or states when-not to use it. The agent can infer prerequisites but not how to choose this over the other creation tools.

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