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

Annotations only tell the agent this is a non-read-only, non-destructive operation. The description adds material behavior beyond that: per-clip credit cost with per-clip refunds on failure, and that it is asynchronous, returning project ids immediately rather than finished clips. These are exactly the economics and timing facts an agent needs before invoking a paid mutation.

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?

Two sentences with zero filler; the pipeline position is front-loaded, then cost, then the async hand-off. Every clause carries information an invoking agent needs.

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 compensates by explaining that the return value is project ids and how to consume them (wait_for_project / get_project for each). Combined with the cost/refund and async disclosure, an agent has everything needed to call this 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 description coverage is 100%, so every parameter is already documented in the schema itself (including that caption_style overrides the plan style). The description adds no syntax, format, or constraint detail beyond the schema, 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 (render), the resource (chosen candidates of a ready plan), the output format (9:16 clips with captions), and its pipeline position (step 2/2 of AI Clipper). This clearly differentiates it from siblings start_clipper (step 1) and get_clip_plan (candidate source).

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 frames itself as step 2/2 of a multi-step flow and names the follow-up tools (wait_for_project / get_project) with the 'for each' caveat. It does not state a when-not condition or spell out the prerequisite that start_clipper and get_clip_plan must have run first, but the step numbering implies it strongly.

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