face_swap

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

No annotations are provided, so the description carries full burden. It only states the basic operation. It does not disclose whether multiple faces are handled, what happens if the source has no face, resolution limits, or whether the result is a new image or modification. The output schema exists but is not referenced.

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?

Single sentence, zero wasted words. The essential information is front-loaded. Perfectly concise for a straightforward operation.

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 the tool's complexity (face swap with 4 parameters, output schema exists, multiple siblings), the description is too brief. It fails to explain failure modes, prerequisites, or output format. The agent is left with many unknowns.

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% (all four parameters have descriptions). The description adds value by clarifying the relationship between the two required parameters (source face transplanted to target). However, it does not add extra syntax or format details beyond the schema. Baseline 3 is appropriate.

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 is a specific verb+resource: 'Replace the face in target_image_url with the face from source_image_url.' It clearly identifies the two images involved and the action, distinguishing it from siblings like face_cartoonize or face_beautify.

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?

No guidance on when to use face_swap versus alternatives (e.g., face_change_age, face_detect_keypoints). No prerequisites, conditions, or exclusions are mentioned. The agent receives no context for choosing this tool over siblings.

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