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

No annotations are provided, so the description carries the burden of explaining behavior. It explains that the whole inner reel plays relative to the origin, that the window length is preserved, and what happens when there was no window. It stops short of stating persistence or failure behavior, but the core side effects are disclosed.

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 description is compact and front-loaded with the main action. Each sentence adds an essential detail: what the origin does, why it matters, the edge-case fallback, and where to find the band id. No filler or duplication.

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 3-parameter tool with no output schema and no annotations, this is well covered: purpose, behavior, edge case, and param source are all present. The only omissions are minor, such as explicit persistence or error behavior, and they do not block correct selection or invocation.

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 already 100%, giving a baseline of 3. The description adds real meaning: start is the TIME ORIGIN and bandId must be a morpha group id from describe_video, which maps directly to how the tool should be invoked. projectId's role is already covered by the schema.

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 uses a specific verb and resource: 'Place an embedded morpha band on the host timeline' and 'set its TIME ORIGIN'. It immediately distinguishes the operation from generic layer commands like move_layer and add_morpha_layer by scoping it to embedded morpha bands and their start frame.

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?

It gives concrete context for when to use the tool: it is 'the fix for the embedded intro doesn't animate', and tells the caller to pass a band group id from describe_video where morpha:true. It does not explicitly enumerate exclusions or alternatives, but the usage scenario and prerequisite are clear enough.

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