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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description still adds real behavioral value beyond them: notes are respelled to fit the new key signature and chord symbols are transposed along with the notes.

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?

Roughly three compact clauses with the core action front-loaded and no filler. The nested parentheticals make it slightly dense to parse, but every sentence carries 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?

With a full-coverage schema and an output schema present, the description need not explain return values, and it covers the two driving parameters well. It is silent on the collection-mode/file flow and on where the transposed result lands, which are minor omissions for a transform tool with structured support.

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 coverage is 100%, so the baseline is 3, but the description adds meaning the schema lacks – that -2 means a tone down, that key uses the nearest direction, and that supplying both key and semitones is what selects the octave. It does not clarify the similarly-named file/save_to/part parameters, which the schema handles.

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 names a specific operation (transposing the MusicXML/score to another key) plus concrete effects – respelling notes and moving chord symbols. It is unambiguous what the tool does, but it never contrasts itself with siblings such as fit_range or extract_part that also manipulate the score.

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?

It explains how to choose between the two transposition modes ('by semitones' or 'to a key', and giving both to pick the octave), which is useful selection guidance at the parameter level. It offers no guidance on when to reach for this tool versus other score-manipulation siblings, so usage is only implied.

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