animate_image

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

No annotations are provided, so the description must carry the behavioral burden. It discloses the API key requirement and return path of the MP4, but omits other behavioral aspects like cost, latency, failure modes, or whether the input image is left unmodified. Adequate for a simple read-like generation tool, but not complete.

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 concise sentences front-load the core purpose and then add necessary context (API key, output path). Every sentence earns its place, with no redundant 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 tool with four parameters, no output schema, and no annotations, the description covers the essential non-schema context: provider requirement, input location, and return format. Minor gaps like expected prompt style or model behavior are secondary given the schema already documents parameters.

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%, so each parameter has a description. The tool description repeats the local file path notion but adds no semantics beyond the schema (e.g., prompt guidance or duration caveats). Baseline 3 is appropriate since the schema already handles parameter meaning.

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 states a specific verb and resource: 'Animate a static image using AI image-to-video (fal)'. This clearly distinguishes it from siblings like generate_video (text/video) or edit_image, and includes the provider and input type, making the tool's purpose unmistakable.

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 implies when to use the tool (when you have a static image to animate) and notes prerequisites (fal API key, local file path), but it provides no explicit alternatives or when-not-to-use guidance. With siblings such as generate_video, more direct routing would improve clarity.

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