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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and openWorldHint=false, so the side-effect sentence largely restates structured data. What it adds beyond that is genuinely new: hard limits (64 KB input, 1 s per call, 1 MB result) and the determinism/Unicode-preservation guarantees, which help an agent size its calls.

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?

Front-loaded with the action, then labeled When / Not for / Side effects / Deterministic / Limits, which is easy to scan. It is duplicated in Spanish and English, roughly doubling length, but each labeled clause carries distinct information.

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 shape needs no explanation, and the description covers the remaining gaps an agent would care about: splitting rules, Unicode handling, determinism, and size/time limits. Nothing needed 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?

Schema coverage is 100% with a single required 'text' parameter documented in-schema, so the baseline is 3. The description adds transformation semantics (how words are split) rather than anything about the parameter itself, so no reason to score higher.

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 texto o un identificador a camelCase') plus the exact word-splitting rule (spaces, punctuation, camelCase/acronym boundaries, Unicode preserved). It also names the sibling case-pascal as the thing it is not, so an agent can separate it from the other nine case-* tools 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?

Explicit 'Cuándo' context (exact transformation/comparison/measurement rather than approximation) and an explicit 'No para' exclusion that names the alternative tool (case-pascal). The routing decision is fully determined by the description.

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