set_note_expression

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

With no annotations at all, the description carries the full burden, and it does disclose two meaningful behavioral traits: omitting indices applies the change to every note (a bulk mutation), and value=null restores defaults rather than deleting. It says nothing about prerequisites (an open project), what happens on an unrecognized abbr, or failure behavior, which is a real gap for a no-annotation mutation 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 core facts are front-loaded and the English sentence is dense and waste-free, but the entire content is then duplicated verbatim in Japanese, roughly doubling length without adding information for a single agent invocation.

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 4-parameter mutation tool with no annotations and no output schema, the definition covers the most important semantics (bulk scope, reset behavior, expression key examples) but omits prerequisites, return/error behavior, and how the target part is identified. Adequate but with clear gaps an agent would hit at call time.

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 definition must compensate, and it does for three of four parameters: abbr (which expression keys exist), value (null means reset), and indices (omitted means all notes). The 'part' parameter is never explained, and the definition does not point to list_expressions as the source of valid abbr values.

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 (set) plus resource (note expression) and enumerates concrete expression keys (vel, vol, atk, dec, gen, bre, clr), so an agent knows exactly what is being modified. It does not explicitly contrast itself with adjacent siblings such as set_curve or set_pitch, 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?

The guidance given ('no indices = all notes', 'value null = reset to default') is about parameter effects rather than when to choose this tool over set_curve/set_pitch or clear_curve. Usage is strongly implied but never stated as a condition or exclusion.

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