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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, but the description still adds real context: no network access, no stored state, determinism, and concrete limits (64 KB JSON input, 1 s per call, 1 MB result). Nothing here contradicts the structured hints.

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?

Well front-loaded with labeled sections (Cuándo / No para / Efectos / Determinista / Límites) and no filler sentences. The full bilingual restatement doubles the length for the same content, which is the main cost against a higher score.

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; the description still covers safety, determinism, size/time limits and the sibling alternative. Nothing an agent needs to invoke this decoding utility 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%, so the baseline is 3, but the description adds practical meaning by naming the encoder precisions typically encountered (5 or 6). That said, the schema allows 1–7, so the description arguably narrows the range without explaining what other precisions would mean.

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 ("Decodifica una cadena Encoded Polyline en puntos lat/lon"), including the precision detail (5 or 6). It also names the sibling it is not (polyline-encode), so the agent can separate the two 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?

Explicit "Cuándo" clause (computing coordinates, distances, bearings or areas from points) and an explicit "No para" clause pointing to polyline-encode for the inverse operation. Both the positive and negative selection conditions are given.

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