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

Annotations already declare readOnly/openWorld=false/idempotent/non-destructive, and the description still adds real value beyond them: explicit side-effect statement (no network, no stored state), determinism guarantee, and concrete limits (64 KB input, 1 s per call, 1 MB result). Those limits are operational facts an agent can't get from the annotations.

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 well front-loaded and organized under clear labels (Cuándo / No para / Efectos / Límites), but the full Spanish and English texts are near-verbatim duplicates, roughly doubling length without adding information. Note also a minor internal inconsistency: the description cites a 64 KB JSON limit while the schema sets maxLength 4096.

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. For a single-param, deterministic pure function, the description covers purpose, routing, safety profile, determinism and resource limits — nothing an agent needs to call it 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?

With a single parameter at 100% schema description coverage, the schema already documents `text` type, requiredness, maxLength and an example. The description adds only behavioral detail (how splitting works) rather than parameter-level meaning, so the baseline of 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 and target format ('Convierte texto o un identificador a CONSTANT_CASE') and immediately specifies the tokenization rule (spaces, punctuation, camelCase/acronym boundaries) plus Unicode preservation. This distinguishes it cleanly from the ~10 sibling case-* converters that share the same verb.

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?

Explicit 'Cuándo:' gives the positive trigger (exact transform/compare/measure rather than approximate) and 'No para:' names the alternative tool (case-detect) with the condition that selects it. The agent does not have to infer anything about routing.

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