compose

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

No annotations are provided, so the description carries the full burden. It usefully discloses the peer-dependency and headless-Chrome requirement plus an 'unavailable' error path, which is real behavioral value. It omits whether the render is long-running/blocking and whether writing to 'output' overwrites an existing file, which matters for a write-producing tool.

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, front-loaded with the core action, followed by the environmental prerequisite. No filler, and both sentences carry new 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 5-parameter tool with no output schema, the description covers the action and the key environmental prerequisite. The remaining gap is the unexplained 'quality' enum and overwrite behavior on 'output', but overall an agent could 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 80%, so the schema already documents composition, output, fps, and format. The description adds no parameter-level detail, and the undocumented 'quality' enum is left without explanation in either place. Baseline 3 is appropriate given the strong schema coverage.

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: renders a HyperFrames HTML composition to video. Clear enough for an agent to grasp the output. However, it does not distinguish itself from the sibling tool 'render', leaving ambiguity about which produces video from a composition versus other media.

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?

The description gives a precondition ('Needs the optional peer @hyperframes/producer and headless Chrome') and the failure mode, which implies when the tool will not work. It never says when to choose compose over render or any other sibling, so routing must be inferred.

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