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

Annotations only declare readOnlyHint and openWorldHint, leaving the return shape to the description — and the description fills that gap by disclosing that the result includes a listening link plus piano and guitar renderings. It is silent on behavior for unrecognized scale names or default scale handling, keeping it out of 5 territory.

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?

Front-loads the core purpose in one sentence and appends the supported values compactly. The enumerated scale list is long but functional rather than padding, since no enum exists in the schema.

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?

With no output schema, the description covers the return content (notes, step pattern, links), and both parameters are documented. Only error/fallback behavior for invalid scale input is unaddressed.

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 coverage is 100% so the baseline is 3, but the schema has no enums and the description supplies the full set of accepted scale names, which is genuine meaning beyond the schema. The root format is left entirely to the 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?

States a specific resource (scale/mode notes and step pattern) and what accompanies it (audio link, piano/guitar visualization), which is unambiguous about what the tool returns. It does not explicitly contrast itself with chord_info or the other music siblings, so it stops short of a 5.

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?

There is no statement of when to reach for this tool versus sibling tools like chord_info or transpose_chords; the long scale list reads as parameter enumeration rather than usage guidance. Retrieval context is only weakly implied by the resource named.

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