ffmpeg__add_fade

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

With no annotations, the description carries the full burden. It discloses the output format ('Returns JSON in stdout with output_path and applied parameters'), the audio fade behavior, and the requirement that at least one duration be positive. However, it does not cover error behavior or file overwrite semantics, leaving some 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 well-structured: a one-sentence purpose, a brief remarks section, and a parameter list. It is front-loaded and avoids unnecessary prose.

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?

The description covers all seven parameters and shares the output format, which is important given the lack of an output schema. It also includes a key constraint. Some edge-case behavior is absent, but for the tool's complexity, the description is largely complete.

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 schema provides no descriptions (0% coverage), so the @param lines are the sole source. Each parameter is clearly explained with defaults and value domains (e.g., fade_color: black or white), fully compensating for the schema's lack of 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 opens with a clear, specific statement: 'Add fade-in and/or fade-out transitions to a video clip.' This specifies the verb (add), the resource (video clip), and the scope (fade transitions), distinguishing it from sibling ffmpeg tools like concat or split.

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 provides no guidance on when to use this tool versus alternatives. The @remarks mention a precondition (at least one duration > 0) but do not clarify use cases or compare with other ffmpeg tools.

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