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

Annotations are minimal (only non-read-only, non-destructive), so the description carries the full burden. It discloses the pipeline (transcription, vision call for subject-aware reframing, crop offset held per clip), the deliberate nontracking to avoid shimmer, the default burned-in captions and approximate timing, and the return fields (reframedToSubject, reframeWhy, captionsBurned). This goes far beyond annotations with actionable behavioral detail. No contradiction with annotations.

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 long but every sentence carries critical operational information. It is front-loaded with the core purpose, then systematically covers input types, restrictions, cost, return shape, caption defaults, and timing caveats. The structure uses clear labels (ACCEPTS, NOT supported, Cost, RETURNS) that make scanning easy, and there is no filler or repetition.

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?

Despite no output schema, the description fully explains what the tool returns (clips[] with mp4 URLs, titles, hooks, captions, scores, timecodes) and how to interpret result fields. It also documents constraints (15s-600MB, 40-min analysis limit), costs, and caveats (approximate timing, unidirectional crop behavior). An agent has everything needed to call this tool correctly and interpret its output.

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%, but the description adds significant value beyond the schema. For example, it explains the default behavior of `captions` (burned by default, delivered bare if no readable speech) and `aspectRatio` (9:16 default for vertical platforms, 'keep' leaves source framing). It also clarifies that `count` is 1-8 with default 4, though the schema already covers that. The description enriches parameter understanding with usage context and edge-case handling.

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 and resource: 'Cut ONE long video into several RANKED, ready-to-post short clips' with explicit target use cases (podcast, webinar, interview, etc.). It clearly differentiates from sibling tools like edit_video, dub_video, and reframe_video by describing the full pipeline (transcribe, select, cut, reframe) and the output format (multiple clips, not a single edit).

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?

Provides explicit when-to-use context and exclusions: acceptable input formats (YouTube, direct files, Hermoso URLs) are listed, and unsupported sources (TikTok/Instagram/Facebook, age-restricted, live) are called out with a fail-fast/refund policy. Also states prerequisites (min length, max size) and cost implications, giving the agent full decision criteria for invocation.

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