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

Annotations already cover the safety profile (read-only, idempotent, non-destructive), so the description's real contribution is the long-poll contract: it blocks, it has a bounded wait, and it returns only events after the supplied cursor. That is meaningful behavioral context an agent cannot get from the schema. It stops short of describing timeout-edge behavior or what an empty result means.

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 with the wait conditions front-loaded and the return value trailing. Every clause carries information, though the semicolon-joined structure is slightly packed for a one-line description.

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 must convey the return shape, and it does: events since the cursor plus an optional decision. Combined with full schema coverage and annotations, an agent has everything needed to call it correctly.

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%, with per-parameter descriptions for since, game_id, and timeout_s (including the default 25 and max 45). The description only echoes those names, so it adds no meaning beyond the schema; 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 (wait) with precise termination conditions — decision requested, game ended, or timeout_s elapsed — and names what is returned. It is clearly distinguishable from non-blocking siblings like get_state, though it never names them explicitly.

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 blocking semantics strongly imply when to call it (await your turn instead of polling), and the 'since' reference implies repeated calls after each turn. However, there is no explicit statement of when to prefer this over get_state, nor any prerequisite or exclusion guidance.

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