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

Annotations already declare readOnly=true, idempotent=true, openWorld=false and destructive=false, so the safety profile is fully covered without the description. The text adds only the useful scope constraint that output is reference data rather than draw results; nothing about caching, locale behavior or freshness is disclosed.

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 trigger condition is front-loaded in the first clause, and the whole definition is two sentences. The first sentence is long and crammed with parentheticals, which slightly hurts scanability but not enough to waste space.

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?

With no output schema, the description carries the return-value burden and does enumerate the reference categories returned. For a zero-parameter, read-only lookup whose annotations already state the safety profile, this is nearly complete; only freshness/format details are absent.

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?

The tool takes zero parameters, so the baseline is 4 and there is no schema content the description needs to compensate for. It still usefully describes what kinds of reference values the caller gets back, which is beyond a bare parameter listing.

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?

The description names a concrete resource (reference data) and enumerates exactly what it covers: today's date in Argentina, the latest draw day, the quiniela jurisdictions/turnos, and the turno schedule. The closing clause 'Returns reference data only, no results' cleanly separates it from result-oriented siblings like get_results or get_number_info.

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?

It gives an explicit trigger ('Use this when you need...') and even supplies representative user phrasings such as '¿a qué hora es la nocturna?'. The 'no results' clause implies that result queries belong elsewhere, but no sibling tool is named outright.

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