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

With minimal annotations, the description carries the burden and does so thoroughly. It discloses content-anchoring ('a stylized moment follows its footage through later cuts'), explains effect limitations (motion_blur 'only reads on movement, does nothing on a static shot'), and warns about layer stacking ('five read as a broken TV'). It also notes the return behavior ('returns the project identity with its result'). No contradiction with 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?

The description is a single dense paragraph, but every sentence earns its place. It front-loads the project scope, then lists effects with inline clarifications. While long, the semicolon-separated list keeps it readable. It could be split into clearer sections, but it remains efficient for the information conveyed.

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 tool with 13 effect variants and subtle caveats, the description is remarkably complete. It explains the whole-video vs. program-seconds behavior, intensity constraints, effect-specific limitations, and the content-anchored nature. It also gives an alternative (enhance_video) and sets expectations about layered effects. An agent has all the information needed to decide and invoke 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 only 33%, but the description adds significant meaning: it explains start/end as program seconds, intensity range and default, and describes each effect kind. project_id and motion_motif are already described in the schema. The description does not explicitly tie parameter names to their explanations, but it covers the critical ones. It compensates well for the coverage gap, though a few parameters like motion_motif are left to 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 clearly states the verb ('Layer'), resource ('program picture'), and scope ('PROJECT-SCOPED: acts only on the explicit project_id'). It enumerates all effect kinds and distinguishes from siblings like remove_stylize and enhance_video. An agent can immediately understand what this tool does and how it differs from alternatives.

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?

Explicit guidance is provided for when to use this tool versus others: 'sharpen'/'denoise' → 'prefer enhance_video, which orders them correctly'; 'stabilize' is 'whole-video only' and cannot fix a whip, walk, or rolling shutter. It also clarifies start/end semantics ('PROGRAM seconds — omit both for the whole video') and intensity range, so the agent knows how to invoke correctly.

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