video_merge

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

No annotations are provided, so the description carries full burden. It mentions merging clips and transition options but doesn't disclose critical behaviors: whether it overwrites existing output files, what video formats are supported, if it requires specific permissions, processing time, error handling, or what the output schema returns. For a mutation tool with zero annotation coverage, this is inadequate.

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 with a clear purpose statement followed by parameter details. It's appropriately sized and front-loaded, though the parameter explanations could be slightly more concise (e.g., combining transition and transitions into one bullet).

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 5 parameters with 0% schema coverage, no annotations, but an output schema exists, the description does a decent job explaining inputs but lacks behavioral context. The output schema means return values are documented elsewhere, but for a video processing tool, details like supported formats, side effects, and error conditions are missing, making it incomplete for safe use.

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 description coverage is 0%, so the description must compensate. It provides meaningful explanations for all 5 parameters: clips (list of paths in order), output_path (auto-generated if omitted), transition (single type with examples), transitions (per-pair overriding), and transition_duration (seconds). This adds substantial value beyond the bare schema, though it could specify format constraints (e.g., file extensions).

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 clearly states the tool's purpose: 'Merge multiple video clips into one.' This is a specific verb (merge) and resource (video clips). However, it doesn't explicitly differentiate from sibling tools like video_edit or video_export, which might have overlapping functionality.

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 is provided on when to use this tool versus alternatives. With many sibling video tools available (e.g., video_edit, video_trim, video_convert), the description doesn't explain if this is for simple concatenation versus complex editing, or prerequisites like file formats.

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