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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds real behavioral context beyond them: the returned artifacts, the fact that the link is public (anyone holding it can join from a mobile), and whether the party permits solo entry along with who has already joined. With no output schema, this return-shape disclosure is genuinely load-bearing.

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 purpose is front-loaded and every clause maps to something an agent needs (return contents, default party selection, alternative tool). It is a single dense run-on sentence with heavy semicolon chaining, which slightly hurts scannability even though no clause is wasted.

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?

This is a read-only, single-optional-param tool with no output schema, so the description must describe the payload — and it does, itemizing each returned artifact plus join policy and current members. Nothing critical for correct invocation appears missing, though overlap with get_party_status and get_whatsapp_link is left unresolved.

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% and the single optional party_id is already documented as a UUID whose omission selects the game of the round in play. The description's clause 'Sin party_id: la partida de la vuelta en juego' restates that schema text rather than adding new meaning. Baseline 3 applies when the schema does the heavy lifting.

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 specific resource (the party invite) and enumerates exactly what it returns: public /play/ link, short code, paste-ready text, and a WhatsApp-opening link, plus solo-join policy and current members. It also names a different tool (add_party_player) for the license-based invite path. It stops short of distinguishing itself from overlapping siblings like get_whatsapp_link or get_party_status, which also surface related artifacts.

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?

Usage is clear from context: reach for this when you need to share a group game with people who will join from their phones, and use add_party_player instead when the invitee has a Badgie account and should be notified in-app. The default behavior with no party_id (falls back to the game of the round in play) is stated. No explicit 'when not to use' beyond the one alternative is given.

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