fablecut_export

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

With no annotations, the description carries the full burden and does so richly: it discloses the browser execution model (open tab or headless Chrome/Edge), the FABLECUT_CHROME env var, the ffmpeg-on-PATH prerequisite, a one-export-at-a-time constraint, and that timeout leaves the export running. This is well beyond what structured fields 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?

Front-loaded with the core purpose, then layers execution model, prerequisites, and async controls. It is dense and somewhat long but nearly every sentence carries operational value; a small amount could be tightened without losing 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?

For a 7-param, side-effecting render tool with no output schema, the description covers prerequisites, execution venue, concurrency, waiting/polling/cancel semantics, and timeout behavior. Nothing an agent needs to invoke it correctly appears to be missing.

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 baseline is 3; the description adds marginal meaning by tying {job} to polling ('poll with {job}') and {cancel:job} to stopping a running export, and by restating the range default ('inPoint→outPoint when set, else the whole timeline'). It reinforces rather than fully re-documents the parameters, so it sits just above 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 and resource ('Render the timeline to a video file in exports/') and immediately differentiates it from siblings by noting it uses the editor's own Fast export compositor and encoding profile. An agent can distinguish it from fablecut_encode_profiles and fablecut_status at a glance.

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 explicit when-to-use guidance: default waits for the file, 'Long edits: pass wait:false, then poll with {job}; {cancel:job} stops one.' Also explains the where modes (auto/tab/headless), making the selection conditions for alternatives concrete rather than inferred.

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