clip_concat

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

With zero annotations, the description carries the full disclosure burden. It does disclose two genuinely informative behaviors: audio is dropped ('video only') and outputs are normalized to a common size/frame rate. But it omits what the tool returns or where output goes, whether input files are modified, and how aspect-ratio mismatches are handled (stretch vs. crop/letterbox).

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?

A single 12-word sentence that front-loads the core action and compresses the two key qualifiers into subordinate clauses. Every word earns its place, with no filler or repetition of the tool name.

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 4-parameter tool with no output schema and no annotations, one sentence is thin. The description never states what artifact the call produces or returns, which an agent needs to chain this with render_start or media_list, and it offers no disambiguation from composition-based sequencing (comp_add_clip) or edge-case behavior for mismatched source resolutions.

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 every parameter is undocumented at the schema level. The description partially compensates by explaining why fps, width, and height exist — they are the normalization target. However, no parameter is individually described, and inputs is only inferable from 'Concatenate videos'; details like aspect-ratio policy or dimension constraints are absent.

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 states a specific verb+resource ('Concatenate videos') with two clarifying qualifiers: '(video only)' and 'normalised to a common size and frame rate.' This makes the operation clear and implicitly sets it apart from audio tools and from simple joining, though it never explicitly names or contrasts any sibling such as comp_add_clip or clip_format_convert.

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 use case is implied: an agent can infer this is the tool for joining multiple video files into a single output. However, there is no explicit when-to-use guidance, no exclusions, and no mention of alternatives — e.g., when concatenation should be preferred over sequencing clips in a composition via comp_add_clip.

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