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

Annotations already declare readOnly=false, idempotent=false, and openWorld=true. The description adds real behavioral context beyond them: moves have a persistent effect (recorded contribution/effects/consequence) and the server explicitly will not choose or play on a participant's behalf. It omits auth/permission details beyond the session token.

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?

Two tight sentences, with the core action front-loaded and the turn constraint following. No filler, though the terse phrasing leaves some ambiguity rather than over-explaining.

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?

For a stateful, non-idempotent mutation with six parameters and no output schema, the description covers purpose and turn behavior but says nothing about failure modes, validation of the move token, or the role of confidence/target_turn. Adequate but with clear gaps.

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 67%, above the halfway mark, and the schema itself documents move, session_id, contribution, and session_token. The description reinforces that the move relates to the current phase but adds no meaning to confidence or target_turn, so it neither compensates for nor enriches the remaining gap.

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 ("Executa uma jogada disponível na fase atual") and adds that it records contribution, effects, and consequence. It clearly signals a game-move action, but does not explicitly separate itself from neighboring game tools like nexo_join_game or nexo_create_game.

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?

The phrase "jogada disponível na fase atual" implies the move must come from the current phase, and "Participantes alternam" hints at turn ordering. However, there is no explicit when-to-use/when-not guidance and no named alternative, leaving usage to inference.

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