REAPER MCP Server

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

No annotations provided, so description carries full burden. Fails to disclose whether changes apply retroactively to existing content, affect the metronome/grid alignment immediately, or require transport restart. Missing safety/scope information.

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?

Single efficient sentence with examples appended. Every word earns its place; no redundancy or boilerplate.

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?

Adequate for a two-parameter setter without output schema, but insufficient for a DAW context where time signature changes have complex implications for existing arrangements. Lacks behavioral context expected for mutation tools.

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?

With 0% schema description coverage, the description partially compensates through examples (4/4 implies numerator=4, denominator=4). However, it lacks explicit mapping instructions (e.g., 'numerator is the top number representing beats per measure').

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?

Clearly states the action (Set) and target (project time signature) with concrete examples (4/4, 3/4, 6/8) that distinguish it from tempo-related siblings like set_tempo. Loses one point for not clarifying scope (project-wide vs track-specific).

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?

Provides no guidance on when to use this versus alternatives, prerequisites (e.g., project must exist), or side effects. Does not mention if this affects existing MIDI items or just future arrangements.

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