midi-mcp

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the action ('Send') but does not cover critical aspects like whether this requires an open MIDI port, potential side effects (e.g., hardware changes), error handling, or response format. The mention of data formatting (bytes 0-127 without F0/F7) is helpful but insufficient for a mutation tool.

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 appropriately sized and front-loaded, with the core purpose in the first sentence and parameter details following. It avoids unnecessary words, though the structure could be slightly improved by integrating the parameter explanation more seamlessly rather than as a separate 'Args:' section.

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 the tool's complexity (mutation with no annotations or output schema) and low schema coverage, the description is incomplete. It lacks information on prerequisites (e.g., open port), behavioral outcomes, error conditions, and what happens after sending the message. For a tool that interacts with external hardware, this is a significant gap.

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?

The description adds significant meaning beyond the input schema, which has 0% description coverage. It explains that 'data' is a list of SysEx data bytes, specifies the valid range (0-127), and clarifies formatting (without F0/F7 framing). This compensates well for the schema's lack of documentation, though it doesn't detail the array's length or other constraints.

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 ('Send a MIDI System Exclusive message') and resource ('SysEx data bytes'), distinguishing it from sibling tools like send_cc or send_note_on that handle different MIDI message types. It precisely defines what the tool does without being vague or tautological.

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 no guidance on when to use this tool versus alternatives, such as send_cc or send_program_change, nor does it mention prerequisites like needing an open MIDI port. It lacks explicit context for usage decisions, leaving the agent to infer based on the purpose alone.

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