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

Goes well beyond the annotations by disclosing the async contract (returns a job_id to poll with get_job), expected latency (1-5 minutes), full cost model (100 credits + 4 per video minute), the 180-minute cap, and refund-on-failure behavior. These are exactly the traits an agent needs beyond readOnlyHint/destructiveHint/openWorldHint.

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, front-loaded with the core action, then input contract, then timing/return, then cost/eligibility. No filler and nothing repeated from the schema verbatim.

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?

For an async, credit-consuming, open-world generation tool with no output schema, the description covers the return value (job_id), the polling path, duration, cost, limits, and licensing. An agent has everything needed to decide and 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 coverage is 100%, so the baseline is 3, but the description adds a genuine constraint the schema cannot express: url and job_id are mutually exclusive alternatives (one or the other), which matters given zero required parameters. It adds no further detail on the tuning params, which is acceptable since the schema documents them.

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 concrete verb and resource ('Cuts a long video into vertical clips') plus the enriched outputs (captions, title, hook, hashtags). An agent can distinguish it from download_video and get_job because the description frames download as a prerequisite and get_job as the follow-up.

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?

Clearly says to pass 'url OR the job_id of a finished download' and restricts use to 'the user's own or licensed content', which is actionable eligibility guidance. It does not explicitly name a sibling alternative to use instead when the source isn't licensed, so it stops short of full when-not/alternative coverage.

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