add_to_timeline_batch

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

With no annotations, the description carries the full behavioral burden and does so thoroughly: it discloses overwrite mode, per-clip result handling, that one failure does not sink the batch, and the exact aggregate status semantics ('success' | 'partial' | 'failure') with placed/failed/total counts. This goes well beyond the schema.

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 dense but every sentence earns its place: purpose, speed rationale, equivalence to the sibling, per-clip parameter support, and result semantics. It is organized and front-loaded, with no filler.

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 batch mutation tool with no annotations and no output schema, the description is remarkably complete. It covers required inputs, overwrite behavior, per-clip failure isolation, return shape, and aggregate status semantics, so an agent has enough to invoke it correctly without external assumptions.

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 already documents both parameters and all nested clip properties in detail (100% coverage). The description adds mild reinforcement about per-clip linkAudio and sourceInPoint/sourceOutPoint and calls them Source-monitor in/out, but it mostly restates what the schema already covers, so the baseline 3 applies.

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 specific verb+resource ('places MANY clips onto one sequence') and immediately distinguishes itself from add_to_timeline by framing this as the fast batch path. It tells the agent exactly what the tool does and how it differs from the closest sibling.

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?

It explicitly names add_to_timeline as the single-clip equivalent and frames the batch as the fast path for rebuilding whole edits, which gives clear context for when to choose it. It does not explicitly state 'do not use for a single clip,' but that is strongly implied by the design.

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