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

With no annotations provided, the description carries the full burden. It describes the output as 'per-dimension comparison + actionable deltas' and gives an example return structure. It implies a read-only comparison but does not explicitly state that no files are modified or mention constraints like sample rate compatibility.

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 bold title, bullet points of dimensions, parameter explanations, and an example usage. Every sentence adds value without redundancy. It is concise yet informative.

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 (mix comparison) and lack of annotations, the description covers the what, why, and how effectively. It includes an example return shape and explains both parameters. However, it could mention prerequisites like matching sample rates or lengths of the two files.

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 input schema has no descriptions (0% coverage), but the description adds meaning: 'filename: Your mix WAV (exports dir or absolute path)' and 'reference: Reference track WAV (exports dir or absolute path).' This compensates well for the schema gap, though it could specify supported file formats beyond WAV.

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 tool's purpose: 'A/B compare your mix against a reference track across all dimensions.' It lists specific comparison dimensions (LUFS, spectral curve, stereo width, dynamic range, spectral centroid) and differentiates from siblings like 'compare_to_profile' by focusing on reference tracks.

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 clear context on when to use: 'This is how you learn how pros mix your genre. Drop in a reference track you admire.' However, it does not explicitly mention when not to use or compare with the sibling 'compare_to_profile', which could be a potential alternative.

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