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

Annotations already mark read-only and non-destructive behavior; the description adds that the result is deterministic and singles out one frequency, plus a scope warning not to infer ownership, licensing, or unpublished availability. This is meaningful beyond the annotations, though not deeply detailed.

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?

Two tight, front-loaded sentences: the first states the trigger and function, the second a boundary. There is no filler or repetition.

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 zero parameters, a read-only annotation set, and an output schema present, the description supplies the needed purpose and boundary. It is slightly less complete because the optional transposition has no corresponding input field, leaving a small ambiguity about how it is requested.

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?

There are zero parameters in the schema, so the 0-parameter baseline of 4 applies. The description's mention of optional concert-root transposition is a conceptual qualifier; the schema offers no field to document, so no further parameter elaboration is expected.

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 verb ('calculate') and object ('one deterministic frequency in an equal division of the octave'), and narrows scope with optional concert-root transposition. This makes the tool's function immediately distinguishable from the scale-generation and release-retrieval siblings.

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 opens with an explicit 'Use this when...' trigger and adds a negative boundary. It does not name sibling alternatives or state when not to use it, so it misses the explicit when-not requirement but still gives clear usable context.

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