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

The description discloses that the tool 'costs credits from the user's Pixly balance,' adding important behavioral context beyond the annotations (readOnlyHint=false, destructiveHint=false). It does not mention whether the operation is asynchronous or what the return value is, but the credit cost is a significant disclosure.

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 two tight sentences: the first states the action and purpose, the second adds two critical caveats (no second frame, credit cost). No filler words, front-loaded with the verb and core utility.

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?

With 6 parameters, no output schema, and a paid operation, the description should explain what the tool returns (e.g., a video URL or job ID) and whether it runs asynchronously. It currently omits both, leaving the agent uncertain about the post-call contract. However, the core purpose and cost are well covered.

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?

The input schema has 100% coverage with descriptions for all 6 parameters, so the schema already carries the semantic load. The description adds minimal param-specific meaning beyond the schema (e.g., reinforcing one-frame requirement), but it does not compensate for or enhance parameter understanding in a meaningful way.

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 ('Turn') and resource ('single listing photo'), clearly stating the tool creates a cinematic clip with a camera move. It lists example moves and explicitly notes 'No second frame needed,' which distinguishes it from siblings like before_after_reel that likely require two frames.

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 use when a cinematic video from a single photo is desired and highlights that no second frame is needed, which suggests a contrast with two-frame tools. It does not explicitly name alternatives or state when not to use it, but context provides clear guidance.

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