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

Annotations already declare readOnlyHint=false and idempotentHint=false, so the mutation semantics are known. The description adds genuinely new behavioral information — the call returns what happened plus the next decision if it is already due — but says nothing about failure modes for an invalid choice or an expired decision_id, and says nothing about irreversibility.

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 sentences, no filler, and the core action is front-loaded ahead of the identifier constraint and the return note. Every clause carries information an agent needs.

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 usefully covers the return value, and the complex nested choice object is documented in the schema itself. What remains thin is error/retry behavior for a rejected or stale decision, which matters for a non-idempotent mutation with 3 required parameters.

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%; game_id and choice are documented in the schema, but decision_id is bare. The description fills exactly that gap by specifying decision_id's provenance (must be one returned by wait_for_turn or get_state), which is the one piece of semantics the schema omits.

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: "Answer the open decision with one of its options." That is enough for an agent to know this is the action-submission tool and to separate it from read-only siblings like get_state or wait_for_turn, which are named as the source of decision_id rather than as competitors.

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?

Gives a concrete prerequisite chain: decision_id "must be the one wait_for_turn or get_state returned," which tells the agent when this tool is callable and what to call first. It stops short of an explicit exclusion (e.g., what to do when no decision is open, or how to recover from a stale decision_id), so it is not a full when/when-not statement.

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