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

With only readOnlyHint=false available, the description carries the behavioral burden and does so thoroughly: it declares all-or-nothing atomicity, enumerates the exact refusal conditions (unknown id, locked track, timeline cap, clip cap, overlap including originals), states that the first offender is named and nothing is copied, and notes the overlap refusal returns the nearest fitting at_ms. That is unusually rich failure-mode disclosure for a mutation tool.

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 core action is front-loaded in the first clause, and every subsequent clause adds a distinct behavioral fact (atomicity, refusal causes, nearest-fit suggestion, return ordering). It is dense and slightly run-on — the refusal list is a long comma chain — but no sentence is 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?

Three required params at full schema coverage, one annotation, and no output schema — and the description compensates by explaining the return value ('Returns new_clip_ids in the order the clip_ids were given'). An agent has everything needed to call it correctly and interpret the result.

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 already 100%, so the baseline is 3, but the description adds genuine meaning: at_ms anchors the earliest copy while the rest keep relative offsets, duplicates in clip_ids count once, and output order matches input order. It stops short of clarifying units beyond what the schema says or how at_ms interacts with clips of differing start times.

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 and resource — 'Copy 1 to 200 timeline clips' — and pins down the resulting placement ('earliest copy starts at at_ms', 'each copy on its original's track'). The batch scope plus offset-preservation semantics make it clearly distinguishable from the singular studio.duplicate_clip and from studio.add_clip_to_timeline.

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 copy semantics imply the usage case (duplicating a group of clips while preserving relative timing), but the description never states when to prefer this over studio.duplicate_clip, studio.shift_clips, or studio.add_clip_to_timeline. An agent must infer the choice from the plural scope alone.

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