REAPER MCP Server

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

With no annotations provided, the description carries full disclosure burden. It mentions the multi-step configuration workflow but creates ambiguity about whether the limiter is added with defaults or if the parameters in the schema are functional. It omits key behavioral details like whether calling this multiple times creates duplicate effects or how to identify the added limiter.

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 two-sentence structure is appropriately concise and front-loaded with the primary action. However, the second sentence earns negative value by providing misleading guidance that conflicts with the input schema, suggesting the description may be outdated or incorrect rather than merely brief.

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?

While it specifies 'ReaLimit' specifically (useful in the audio production context), the description is inadequate for a 2-parameter tool with 0% schema coverage. It fails to explain the parameters, their valid ranges, or the relationship between direct parameter passing versus the suggested sibling-tool workflow.

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%, requiring the description to compensate. Instead of explaining threshold_db and release_ms, the description confusingly instructs users to ignore these parameters and use get_fx_parameters and set_master_fx_parameter to configure values, directly undermining the schema's intent and leaving the actual parameters undocumented.

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 clearly states the specific action ('Add ReaLimit'), the target resource (ReaLimit plugin), and the location (master track), distinguishing it from generic alternatives like add_master_fx or add_fx.

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 provides workflow sequencing guidance ('After adding, use set_master_fx_parameter...') which implies this is part of a multi-step process. However, it fails to clarify when to choose this tool over add_master_fx, and creates confusion by suggesting parameter configuration via sibling tools rather than through this tool's own parameters.

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