sketch_song

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

No annotations are present, so the description bears the full burden. It usefully discloses that output is ordinary MIDI that can be edited afterwards and that the result is one repeated loop rather than an arrangement. It does not state side effects such as what tracks/items get created, whether existing project content is overwritten, or what happens to parts lacking a plugin (only the schema mentions empty tracks).

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-loaded with the action and its outputs, and every sentence adds something (what is built, what profile drives it, editability, loop/arrangement scope). The first sentence is dense with a long parenthetical, but nothing is redundant.

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 9-parameter creation tool with no annotations and no output schema, the description conveys the outcome, the driving genre profile, and the editability/loop-scope caveat well. Remaining gaps are side-effect details (track/item creation, empty-track behavior) that an agent would still want before calling.

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 89%, so the schema already documents nearly every parameter (key, bars, seed, parts, tempo, instruments, progression). The description adds no parameter-level syntax or format detail beyond what the schema provides, so the baseline 3 is appropriate.

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 first sentence states a specific verb (Builds) and resource (a genre sketch) and enumerates exactly what is produced: tempo, drums, bassline, voiced/comped chords and melody. The genre-profile parenthetical and the closing sentence further pin down scope, so an agent can distinguish it from narrow siblings like write_bassline or add_drum_pattern.

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?

Usage is implied rather than stated: 'It's one loop repeated: a starting point for a song, not the arrangement' tells the agent this is a scaffolding tool, not a full arrangement generator, which is useful scoping. However, no sibling alternatives (add_genre_groove, write_bassline, write_melody, add_chord_progression) are named and there is no explicit when-to-use/when-not-to-use guidance.

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