Place a marker at a specified time in a REAPER project to label song sections or cues, optionally naming and coloring it, and return its index.
Add a marker at a position.
Args: position: Position in seconds. name: Marker name. color: Marker color (0 = default).
Returns: Object with marker index.
| Name | Required | Description | Default |
|---|---|---|---|
| name | No | ||
| color | No | ||
| position | Yes |
Changes observed during successful MCP inspections.
v1.7.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations provided, so the description carries full burden. It states a return object with marker index, which is helpful, but doesn't mention any behavioral traits like project state requirements, undo behavior, or side effects. For a mutation tool with no annotation coverage, this is a significant gap.
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?
Efficient and front-loaded: the purpose is stated first, followed by parameter details and return value. No wasted words, though the formatting mimics docstring style with 'Args:' and 'Returns:' rather than natural prose.
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?
Given no annotations, no output schema, and 0% schema description coverage, the description provides basic parameter semantics and return value. However, it lacks behavioral context (e.g., does it require an open project? What happens on failure?) and usage guidance, making it minimally adequate.
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 0%, so the description must compensate. It provides meaning for 'position' (seconds), 'name' (marker name), and 'color' (0 = default), which is essential since the schema lacks descriptions. However, it doesn't specify units or constraints for color beyond default.
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+resource ('Add a marker') clearly. Distinguished from siblings like delete_marker, get_markers, go_to_marker by the 'add' verb. Missing differentiation from add_region, but that's a minor concern.
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?
No guidance on when to use this vs. alternatives like add_region or go_to_marker. Implies usage from the verb but provides no context or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.