preview_timeline

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

With no annotations provided, the description carries the burden of behavioral disclosure. It explicitly states 'No edits are applied by this call,' which prevents an agent from assuming it is a destructive operation, and it discloses that a duplicate is opened while the original is retained. This is useful context 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 concise and front-loaded: the first sentence states the core action and purpose, and the second adds a non-destructiveness guarantee plus a short workflow. Every sentence earns its place 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?

The description covers the workflow and safety guarantee well, but it omits any explanation of the optional 'name' parameter and does not mention prerequisites such as an already-open active timeline. It is sufficient for a no-argument call, but not fully complete for agents that may want to supply the optional parameter.

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 has one optional parameter, 'name', with no description and no description coverage in the tool description. The description never mentions this parameter, so an agent cannot know whether 'name' refers to the preview timeline's name or something else. This is a clear gap, even though the parameter is optional.

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 clearly states the action: 'Duplicate and open the active timeline for reviewing edits while retaining the original.' This is a specific verb + resource + purpose, and it naturally differentiates the tool from siblings like open_timeline by emphasizing duplication and non-destructive review.

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 description gives an explicit workflow: get fresh clip IDs with timeline_overview, edit the preview, then use compare_timelines before accepting. It clearly explains when to use this tool in a review sequence, though it does not explicitly state when not to use it or name direct alternatives.

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