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

Annotations only declare readOnlyHint=false, so the description carries the rest of the burden and does so: it discloses the exact placement behavior, an explicit failure mode (refuses when there is no room after the original), and the return value (new clip id). It does not say what happens to overlapping clips or whether the failure is an error versus a no-op, which keeps it short of a 5.

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?

Three short sentences, each front-loaded with distinct information: what it does, when it fails, and what it returns. No filler or restatement 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?

With no output schema, the description usefully states the returned new clip id, and it names the refusal condition; the mutation semantics are consistent with readOnlyHint=false. The remaining gap is disambiguation from studio.duplicate_clips, which an agent needs before choosing this tool.

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 only 50% (project_id is documented in-schema, clip_id is not). The description implies clip_id identifies a clip on a timeline but adds no format, scope, or constraint detail to compensate for the undocumented parameter.

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 (copy a timeline clip) plus the placement rule (immediately after the original, same track), which is concrete and unambiguous. However, it never distinguishes itself from the close sibling studio.duplicate_clips, so an agent cannot tell from the text alone which of the two to pick.

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?

There is no when-to-use / when-not-to-use guidance and no mention of the plural sibling duplicate_clips, which is the obvious alternative for this operation. The only conditional information is a behavioral precondition (no room after the clip), not routing guidance.

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