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

Annotations already cover readOnly/idempotent/non-destructive/closed-world, and the description adds genuinely new behavior facts: deterministic, no LLM call, no cost. It stops short of describing the output shape (a prompt string? object?), which would have made it a 5.

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 tight sentences with the purpose front-loaded and the behavioral caveat immediately after. No filler.

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?

No output schema exists, yet the description never says what the prepared prompt looks like or how it is returned. Combined with the undescribed nested customization object, an agent can call the tool but cannot make full use of its inputs or predict its result.

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?

With 0% schema description coverage, the description must carry parameter meaning, and it only covers two of three: 'recipe ID' for id and 'project brief' for brief. The nested customization object (accent, duration, aspectRatio) is never mentioned, leaving its most complex parameter undocumented.

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: 'Prepare a motion prompt' from a recipe ID and project brief. That distinguishes it from the lookup-oriented siblings search_motion and get_motion, though the contrast is implied rather than stated.

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 clarifies the tool is a deterministic text-preparation step that does not render or spend money, which edges toward usage guidance. But there is no explicit 'use this before X' framing or named alternative, so the when-to-use case is only inferable.

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