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 safety profile is fully covered. The description earns credit beyond that by disclosing the return contents — new key name, Camelot code, and a qualitative naturalness note — which is meaningful since no output schema exists.

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?

A single front-loaded sentence that covers the operation, the inputs' effect, and the outputs with zero filler. Nothing is repeated from the schema or annotations.

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 only two fully documented parameters, rich annotations, and no output schema, the description supplies exactly the missing piece: what the tool returns. An agent has everything needed to select and 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 coverage is 100% and the schema already documents both parameter shapes in detail (accepted key formats, negative-is-down, ±12 bounds). The description's 'up or down by semitones' merely restates the schema's semitone semantics, adding no format or boundary detail of its own, so baseline 3 is correct.

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 and resource ('Moves a key up or down by semitones') and even previews the outputs (new key name, Camelot code, naturalness note). It doesn't explicitly distinguish itself from the sibling `camelot` tool, which presumably also deals with Camelot codes, so an agent might briefly wonder which to pick for a key-to-code conversion.

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?

No explicit when-to-use or when-not-to-use guidance, and no named alternatives. Usage is strongly implied by the transposition semantics, but the sibling `speed_pitch` also alters pitch (and therefore key), and the description never clarifies which tool to reach for in that overlap.

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