overlay_clip

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

With no annotations provided, the description bears the full responsibility for behavioral disclosure. It only states the basic action and lacks information about whether the operation mutates the base clip, creates a new clip, or any side effects. It does not mention default timing, positioning behavior, or opacity handling, leaving significant gaps.

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, compact sentence that immediately conveys the core purpose. It is well-structured and front-loaded, with no wasted words.

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 8 parameters and no annotations, this description is minimal. While the output schema likely explains the return value, the description omits important operational context such as whether the base clip is modified, how the overlay is timed, and any limitations. It barely meets the minimum threshold.

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 documents all 8 parameters with thorough descriptions (100% coverage), so the baseline is 3. The tool description adds no additional parameter semantics beyond what the schema already provides, though it does hint that overlay clips can be text, watermark, or video, which aligns with schema descriptions.

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 clear verb ('Place') and identifies the resource ('one clip on top of another') with concrete examples (text, watermark, picture-in-picture), making the tool's function unambiguous. It distinguishes from siblings like concatenate or trim by specifying the compositing action.

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 usage for compositing overlays and provides concrete use cases (text, watermark, PiP), which gives clear context. However, it does not explicitly state when not to use this tool or mention alternatives, so it falls short of a 5.

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