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

With no annotations, the description carries the full burden. It explains the algorithmic behavior for each mode: 'move every other note up by spread_octaves octaves' for open, 'collapse all chord tones into the lowest possible octave' for close, etc. It also discloses the return values. However, it does not explicitly state whether the tool modifies the region in place or if any permissions are required, which is a minor gap.

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 with clear sections: an overview, mode-by-mode explanations, parameter details, return values, and a usage example. It is longer than necessary but every sentence contributes useful information. The organization aids readability and quick scanning.

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?

The tool has an output schema, so return values need not be explained, yet they are listed for clarity. The description covers the core transformation logic, parameter semantics for most parameters, and includes practical examples. It falls short on clarifying side effects (e.g., whether the original notes are overwritten or if the operation is reversible), which is important for an editing tool. Overall, it is quite complete for its complexity.

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 must compensate. It thoroughly explains 'mode', 'chord_position', and 'spread_octaves' with concrete examples and ranges. However, the required parameters 'unit_index', 'track_index', and 'region_index' are not described at all; the example call (spread_voicing(0, 2, 0, 4.0, ...)) provides a hint but is insufficient for full understanding. The description adds value but does not fully fill the schema gap.

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 function: 'Spread or compact a chord voicing — open vs close harmony.' It specifies a precise verb+resource pair and differentiates itself from sibling tools by focusing on chord voicing spacing. The detailed mode explanations (open, close, drop2, drop3) further clarify its scope.

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 for when to use each mode, e.g., 'open' for jazz piano sounds, 'close' for tight block chords, and 'drop2' as a classic jazz comping technique. It does not explicitly name alternatives but gives enough contextual guidance for an agent to choose among modes. It lacks explicit exclusions or comparisons to other transformation tools.

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