mcp_opendaw_create_harmony_line

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

With no annotations, the description carries the burden and largely delivers: it explains the diatonic shift, key guarantee, velocity scaling, and that it returns created notes. It does not explicitly warn about overwriting existing target content, but it clearly states the source is read (not modified) and describes the target creation behavior with -1.

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 well-structured with front-loaded purpose, interval bullets, use-case list, and parameter explanations. It's longer than minimal, but each section serves a purpose; the musical style references add useful context without being rambling.

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 11 parameters and no annotations, the description covers the algorithm, parameter meanings, use cases, and return value. It doesn't detail error cases or prerequisites (e.g., source must contain notes), but an existing output schema and the detailed parameter exposition make it reasonably complete.

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%, and the description fully compensates. It explains interval values with musical meaning (third, sixth, fifth, fourth, octave), root_note+scale guarantee, direction, velocity_scale default, and the source/target unit/track/region semantics. This goes well beyond the bare schema.

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 opens with a clear, specific verb+resource: 'Create a harmony line from an existing melody using diatonic intervals.' It distinguishes itself from siblings like create_harmony or create_chorale by emphasizing a parallel harmony line derived from an existing melody, which is a distinct function.

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 use cases: 'Essential for: vocal harmonies, string pads behind melody, guitar harmonies, counter-melody foundation, thickening lead lines.' This tells the agent when to use the tool, though it doesn't explicitly name alternatives or exclusion criteria.

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