reaper_insert_trackInsert a new track into a REAPER session at a given index, or append it at the end. Returns the index of the inserted track.
Insert a new track at the given index (0-based). Omit index to append at the end. Returns the new track's index.
| Name | Required | Description | Default |
|---|---|---|---|
| name | No | Track name | |
| index | No | 0-based position; omit to append |
Changes observed during successful MCP inspections.
v0.1.0Does 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 states that the action is an insert, that it is index-based, and that it returns the new track's index. However, it does not mention side effects such as shifting existing tracks, project mutation, or any prerequisites. This leaves some behavioral transparency gaps.
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 two sentences that deliver all key information upfront: the action, the parameter behavior, and the return value. Every clause earns its place with no padding or ambiguity.
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?
Even with no output schema and no annotations, the description provides enough for calling this simple two-parameter tool: insertion point, append behavior, and return value. Minor gaps remain (e.g., whether existing tracks shift), but nothing critical prevents correct invocation.
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 the baseline is 3. The description reinforces the index parameter's semantics (0-based, omit to append), but this is redundant with the schema description. It adds no extra meaning beyond what the schema already 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 concrete verb and resource—"Insert a new track"—and specifies the index location, distinguishing this from sibling tools like reaper_delete_track and reaper_set_track_name. It is unambiguous what the tool does and what it returns.
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 clear contextual guidance on the key usage decision: "Omit index to append at the end." It explains how to control insertion position, though it does not explicitly name alternative tools or exclusions. The context is clear and sufficient for a simple create operation.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.