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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety and determinism profile is fully covered by structured data. The description's only added behavior is that results come back in pounds, kilograms and Newtons, which is modest extra context for a pure computation.

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 sentences with zero filler. The purpose and output units are front-loaded in sentence one, and the optional cross-reference is deferred to sentence two.

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 an output schema present, the description need not explain return values, and annotations cover the safety profile while the schema fully documents all three parameters. The only remaining gap is the absence of any stated precondition (e.g. gauge/scale-length validity), which is minor for a deterministic physics calculation.

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 100%: each of the three required parameters has a type, range constraint, and an example (329.63 Hz for E4, 0.010 for a light high E, 25.5 for a Stratocaster). The description adds nothing beyond the schema, so the baseline 3 applies.

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 (Calculate) and resource (guitar or bass string tension) and names the output units, which is exactly what an agent needs to distinguish it from the ~250 other calculate_* siblings. It is unambiguous and self-contained.

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?

Usage is implied by the narrow, self-evident domain (string tension for guitar/bass), but the description gives no explicit when-to-use condition and no exclusion. The only routing hint is a pointer to list_bundles for related 'musique' calculators, which is a cross-reference rather than guidance on when this tool applies.

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