theory_progression

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered; the description's 'Deterministic' largely restates idempotentHint. It does add useful output-purpose context ('voiced, voice-led notes ready for clips.write_midi'), but with no output schema it never describes the shape of the returned note data, which is the main missing behavioral detail.

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?

Two tight sentences plus a routing clause; the core action is front-loaded and every clause (input modes, optional bass/pattern, determinism, alternative tool) carries distinct information.

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 a 5-parameter tool with nested objects and no output schema, the description covers purpose, input modes, performance options, determinism and the sibling alternative. It stops short of describing the returned note structure and how key/mode constrain the generated/parsed chords, leaving a small 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?

Top-level schema coverage is only 40%, but the description compensates by mapping the three input modes onto chords/library/generate (an exclusivity the schema never states) and by citing perform.bass and perform.pattern with example values ('arpeggios, pulses, strums'). The nested field descriptions in the schema carry the rest, so only the 'key' object is left implicit.

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 verb and resource ('turn a chord progression into voiced, voice-led notes') and names the downstream consumer (clips.write_midi). It is immediately distinguishable from the sibling clips.write_progression, which the description explicitly routes away.

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?

Names the three input modes (text, library, generated), the optional performance layer, and the explicit alternative: use clips.write_progression to write directly into a clip with its chord lane. An agent can pick between theory_progression, clips.write_midi and clips.write_progression without opening a schema.

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