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

Annotations only declare the generic safety profile (not read-only, not destructive, not idempotent). The description goes well beyond them: it discloses that each participant sees only their own assignee, that the full result is never returned, the exact return artefacts (private link per person, public group page, organiser admin link), and operational limits (3–100 distinct participants, no emails, deletion after 90 days).

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 core purpose is front-loaded in the first sentence, followed by examples, return values and limits in a logical order. It is somewhat long because every sentence is duplicated in Spanish and English, which is redundant padding for a reader who understands either language.

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, and the description compensates fully by enumerating the three returned links and warning that the full draw result is never returned. Combined with the participant limits, exclusion behaviour and retention policy, an agent has everything needed to call and explain the tool.

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 description coverage is 100%, so all six parameters are already documented in the schema, including the participant count bounds and the exclusion pair format. The description restates the 3–100 participant limit and the exclusion concept but adds no syntax or format detail beyond what the schema provides, so the baseline 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 resource: it performs the Secret Santa draw on the server and generates one private link per participant. It is immediately distinguishable from siblings like crear_encuesta, crear_eleccion_fecha or anadir_gasto, which handle polls, dates and expenses rather than a draw.

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?

Provides three concrete invocation examples ('organiza un amigo invisible con Ana, Luis, Marta y Pablo, presupuesto 20 €', the office variant with exclusions, the family variant), which gives clear context for when to use it. It does not, however, name an alternative tool or state when not to use it.

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