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

No annotations are provided, so the description carries the full burden. It explains the core behavior (accent strength from beat position), lists all accent patterns with meanings, describes interpolation for off-beat notes, and states the return value ('Returns count of notes accented and per-level breakdown'). It does not explicitly state that existing velocities are overwritten or whether undo is possible, but the behavior is well disclosed for a creative 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 longer than average but earned every sentence: it uses clear headings, bullets for patterns, a compact parameter list, and a concise example. It is front-loaded with the main purpose and never wastes words on tautology or repetition of schema info.

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 7 parameters, no annotations, and an output schema the description still covers all essential aspects: what the tool does, all patterns, interpolation behavior, parameter explanations, use cases, and return value. The example further grounds the abstraction. This is complete for an agent to invoke it correctly.

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 0%, so the description fully compensates by defining every parameter: unit_index, track_index, accent_pattern with allowed values, strong/medium/weak_velocity with ranges (0-1), and region_index with default meaning. The example additionally demonstrates usage, making parameter semantics exceptionally clear.

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 opens with a specific verb and resource: 'Apply beat-aware velocity accents to notes based on their position.' It clearly differentiates from the sibling tool apply_velocity_pattern by explicitly noting the difference (beat position vs. note index), so the agent can select it correctly.

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 explicitly contrasts with 'apply_velocity_pattern (which cycles by note index)' and provides a use cases list ('Make drum patterns feel groovy', 'Add natural dynamics to programmed basslines', etc.). This gives clear guidance on when to use the tool and names an alternative, satisfying the 'when/when-not/alternatives' criterion.

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