add_caption_sequence

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

No annotations are provided, so the description carries the full behavioral burden. It says nothing about whether a caption track must already exist for trackIndex, whether existing captions are overwritten, whether the operation is undoable, or what is returned — all material for a mutation tool that adds timeline items.

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?

Two sentences, front-loaded with the operation and followed by the caption structure. The marketing-flavored 'perfect for' clause is mild filler but does convey legitimate use cases, so little is wasted.

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 schema fully documents the six parameters and there is no output schema, so the description needn't explain return values. But for a timeline-mutating batch tool with zero annotations, the absence of any note on caption-track prerequisites or overwrite behavior leaves a real gap.

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 100%, so all six parameters (including defaults for scale, template, positionX/Y) are already documented. The description only restates that each caption has text, start, and duration, adding no semantics beyond the schema.

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?

States a specific verb and resource ('Add multiple timed text captions in sequence') and clarifies the batch nature versus a single-caption call. It does not, however, distinguish itself from close siblings like add_caption or add_tiktok_caption, even though it explicitly invokes the 'TikTok-style captions' use case that the latter presumably owns.

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?

Use cases (word-by-word captions, lyrics sync, subtitle overlays) imply when the tool fits, but there is no explicit when-not guidance and no named alternative for single captions or for the TikTok-specific sibling. The agent must infer routing from the examples.

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