Modify an existing caption segment's text, start time, or end time to correct or adjust captions in Adobe Premiere Pro.
Update the text or timing of an existing caption segment
| Name | Required | Description | Default |
|---|---|---|---|
| text | No | New caption text | |
| endTime | No | New end time in seconds | |
| startTime | No | New start time in seconds | |
| trackIndex | Yes | Caption track index | |
| captionIndex | Yes | Caption segment index |
Changes observed during successful MCP inspections.
v1.0.0Does 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 indicates a mutation ('Update') but does not disclose permissions, reversibility, partial-update behavior, or what happens to unspecified fields.
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 entire definition is a single front-loaded sentence with no filler. It communicates the core action efficiently.
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 simple mutation tool with full schema coverage and no output schema, the description is minimally adequate. However, with no annotations, it could do more to explain prerequisites, required track/caption targeting, and side effects.
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 five parameters are already documented in the schema. The description only echoes text and timing updates, adding no syntax, constraints, or meaning beyond what the schema provides.
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 states a specific verb, resource, and scope: update an existing caption segment's text or timing. The word 'existing' distinguishes it from sibling tools like add_caption and remove_caption without requiring schema inspection.
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 phrase 'existing caption segment' implies the tool should be used only when a caption already exists, but it does not explicitly name alternatives or state when not to use it. Usage is therefore inferable but not fully guided.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.