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

The side-effect and determinism statements largely restate annotations (readOnlyHint, idempotentHint, openWorldHint, destructiveHint), which is redundant. What genuinely adds value is the disclosure of operational limits: 64 KB input, 1 s per call, 1 MB result. Those limits are information an agent cannot get from the annotations or schema, though the redundant safety sentences dilute the contribution.

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 labeled structure (When / Not for / Side effects / Limits) is front-loaded and easy to scan. However, the entire content is duplicated in Spanish and English, roughly doubling length with near-zero marginal information for a given reader, and the safety sentences repeat the 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?

An output schema exists, so return values need no explanation. With purpose, exclusions, determinism, and size/time limits all covered, an agent has everything required to invoke this correctly and to know its bounds.

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% and every parameter, including decimals with its default and 0-12 range, is documented there. The description only reinforces the semantics of part and whole via the formula; it says nothing about decimals or rounding behavior, so it stays at the baseline rather than adding meaning beyond the schema.

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 precise verb and resource with the actual formula (part / whole × 100), so there is no ambiguity about what is computed. It explicitly contrasts itself with the sibling percent-change tool, letting an agent choose between them without opening either schema.

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?

Gives an explicit 'When' condition (result must be exact or reproducible rather than estimated) and an explicit 'Not for' excluding percent-change with the sibling named. This is the strongest form of routing guidance.

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