create_montage

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

No annotations are provided, so the description must disclose behavior. It covers the rendering process (Ken Burns, crossfade), energy cost (~200), async nature with polling instructions, and output format. It lacks mention of potential failure modes or error handling, but otherwise transparent.

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, well-structured paragraph. It front-loads the main purpose, then details effects, async behavior, and usage guidance. Every sentence serves a purpose with no redundancy.

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?

Given no output schema, the description adequately covers return value (hosted MP4 URL) and polling flow. It fully explains the 3 parameters and async workflow. The complexity is moderate and all key aspects are addressed.

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 100%, but description adds context: image_urls order matters, external URLs are fetched and stored, music presets are listed with default, aspect ratios have use-case hints (vertical for Reels). This goes beyond raw schema definitions.

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 it assembles a slideshow video from photos with specific effects (Ken Burns, crossfade). It distinguishes from sibling tools like generate_video (AI video) and create_travel_poster (static image) by specifying the photo montage use case.

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 explicitly says 'Use when the user wants a photo montage / slideshow / turn these pictures into a video / reel.' It provides clear usage context but does not mention when *not* to use or compare with alternatives, though sibling tools exist.

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