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

With no annotations, the description carries the full burden and does disclose meaningful behavior: it is free and deliberately excludes the question, answer, and year. This tells the agent exactly what data it will and won't receive, though auth requirements or rate limits are not mentioned.

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?

A single dense sentence that front-loads the key attribute ('Gratis') and then the content boundaries. Every clause earns its place with no filler.

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?

There is no output schema, so listing the returned metadata fields (título, categoría, dificultad, fecha) usefully compensates. For a simple 1-parameter read tool this is essentially complete, missing only the explicit alternative for routing.

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 single locale parameter is fully documented in the schema (100% coverage) with its 'en'/'es' values, so the description need not elaborate. It adds no parameter meaning beyond the schema, which is the expected baseline here.

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 the resource (today's trivia) and enumerates what it returns (título, categoría, dificultad, fecha), and distinguishes itself from the fuller sibling by exclusion (sin pregunta, sin respuesta). An agent can tell it apart from get_today_trivia, though it never names the sibling.

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?

'Gratis' implies a use condition (pick this when you don't need the question/answer, or when cost matters), suggesting the full-trivia sibling is the alternative. However, no alternative is named and there is no explicit when-to-use or when-not-to-use statement.

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