mcp_opendaw_set_audio_region_fade

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

With no annotations, the description carries the full burden and does well by explaining the Fading object's parameter semantics, the -1 skip behavior to preserve current values, and that the tool returns updated fade values. It does not disclose error behavior for invalid indices or edge cases like setting a slope without a duration, but adds substantial context beyond the bare operation.

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: a one-line summary, conceptual explanation of fades and slopes, the skip rule, a per-parameter reference, and a return note. There is minor redundancy between the Fading object explanation and the parameter list, but every section serves a purpose and the length is justified by the 7-parameter complexity.

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?

For an unannotated, 7-parameter mutation tool, this description covers the purpose, all parameter meanings, the do-not-change sentinel (-1), and the return value. The main gaps are lack of error handling details and explicit interaction with related tools, but the core usage is fully and clearly explained.

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 compensates excellently. It lists every parameter with units (seconds for fades), ranges (0-1 for slopes), and the -1 skip rule, and it maps the conceptual Fading fields (in, out, inSlope, outSlope) to the actual parameter names, adding meaning far beyond the schema's bare type declarations.

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 'Set fade in/out on an audio region,' a precise verb+resource statement that clearly identifies the tool's function. It then elaborates on the Fading object and its four parameters, distinguishing it from sibling tools like set_audio_region_gain and copy_region_fades.

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 detailed explanation of fade durations, slopes, and the -1 skip mechanism provides clear context for when to use this tool: when adjusting an audio region's fades. However, it does not explicitly mention alternatives or exclusions, such as when to prefer copy_region_fades for copying existing fade settings.

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