Render the current project to an MP4 in the cloud

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

Annotations only indicate non-read-only and non-destructive; the description adds crucial behavioral details: it validates the project, consumes render credits, requires an API key, runs synchronously, and returns a downloadable URL. These go well beyond the structured annotations.

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 sentences, front-loaded with the core action and outcome, followed by cost/alternative, then performance characteristics. Every sentence earns its place; no fluff.

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?

Even with an output schema present, the description covers validation, cost, auth, synchronous behavior, and an alternative tool. It gives the agent all necessary context to decide whether to use this tool and what to expect.

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 covers 100% of parameters with detailed descriptions (resolution enum, project_id omission rule). The description adds the 'validates' and 'current project' framing but doesn't materially extend parameter semantics beyond what the schema already provides. Baseline 3 is appropriate.

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?

The description clearly states the tool renders the current project to a download-ready MP4 on Clipkit's servers, distinguishing it from siblings like open_in_editor and preview_still. The verb 'render' and specific resource 'current project' make the purpose unambiguous.

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 says this is the paid path, mentions open_in_editor as a free alternative, and notes the need for CLIPKIT_API_KEY. It also warns about synchronous, potentially slow rendering, giving clear context on when to choose this over alternatives.

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