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

Annotations declare a non-read-only, non-idempotent write, and the description adds the crucial cost/destructive-to-credits behavior, the quote gating, and the async job return (job now, files as links when done). This goes well beyond what the annotations provide.

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?

The output job, credit spend, quote gating and presenter preconditions are front-loaded in a compact block with no filler. Sentences are long and dense, but every clause carries operational 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?

Despite no output schema, the description explains the return behavior (a job, later listing the ad's files as links) and the no-quote estimate path. For a complex, credit-spending, multi-parameter tool, an agent has everything it needs to call 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 schema documents all 11 parameters, giving a baseline of 3. The description still adds cross-parameter meaning the schema does not, notably the quote-to-estimate relationship, presenter prerequisites, and that testimonial basis relies on reviews.

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?

Specific verb ('Makes') plus resource ('UGC-style ad') with the input basis (product and template or feature) spelled out and example features named. It is clearly distinguishable from siblings like ugcfans_make_video, ugcfans_make_image and ugcfans_make_performance.

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 directs the agent to call ugcfans_estimate first and pass its quote, and states the fallback behavior when no quote is given ('returns the cost and makes nothing'). It also states presenter prerequisites (saved, portrait, recorded consent for a real person).

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