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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is partly redundant. The description nevertheless adds genuinely new context: determinism, no network/stored state, and concrete limits (64 KB input, 1 s per call, 1 MB result). The absolute-zero rejection is a useful behavioral constraint the annotations cannot express.

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?

Each language version is front-loaded and efficient, but the full text is duplicated in Spanish and English, roughly doubling length for a single agent. The duplication is defensible given the Spanish title, yet it is waste from the consumer's perspective.

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?

Output schema exists so return values need no explanation, and the description covers determinism, side effects, size/time limits and the absolute-zero boundary. Nothing an agent needs to call this correctly is missing.

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%, including the 'omit for all' behavior for the optional 'to' parameter, so the schema carries the parameter burden. The description only adds the semantic frame 'affine conversion', which is real but modest added value over 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 specific verb and resource ('Convierte temperaturas entre Celsius, Fahrenheit, Kelvin y Rankine'), enumerates the supported units, and names an edge case (rejects below absolute zero). It also explicitly separates itself from the sibling convert-energy, so an agent can disambiguate without opening a 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?

Provides explicit 'When:' and 'Not for:' clauses, naming convert-energy as the alternative for energy conversion. This is the when/when-not/alternatives structure at full strength.

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