REAPER MCP Server

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

Discloses critical behavioral details not in annotations: MIDI channel 9 assignment and step-sequencer mechanics, though omits whether it creates new media items or modifies existing content.

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?

Perfectly structured: purpose first, then mechanics, character legend, example, and technical constraint—every sentence earns its place without fluff.

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?

Covers the unique pattern format comprehensively but leaves significant gaps regarding numerical parameter semantics and return behavior given no output schema exists.

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?

Excellent explanation of 'pattern' parameter syntax/semantics, but fails to compensate for 0% schema coverage on 'start_position' (units), 'beats' (function), and 'repeats' (behavior).

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?

Specific verb ('Create') + resource ('drum pattern') and clearly distinguishes from sibling tools via unique step-sequencer string approach.

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 clear usage context through character legend and example pattern, but lacks explicit 'when not to use' guidance versus alternatives like add_midi_note.

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