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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered structurally. The description adds real behavioral context beyond that: the return value changes across the round lifecycle (pre-lock state vs post-lock revealed seeds and winner) and it discourages polling loops. It does not say what happens for an invalid or unknown game hash.

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?

Three sentences, front-loaded with the returned content first, then usage, then the routing alternative. No filler or restatement of the tool title.

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 does the work of enumerating returned fields, which is the key gap it needed to fill for a state-read tool. Annotations cover the read-only profile. The only notable omission is error/empty behavior for an unknown game hash or a room with no active round.

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%, with the single `game` parameter documented as 'gameHash from list_rooms, or "arena"', so the schema already carries the semantics. The description adds nothing about the parameter; 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 room's current round) and enumerates exactly what it returns: phase, seats, pot, timings, and post-lock revealed seeds and winner. This sharpens it against siblings like list_rooms (enumeration) and wait_for_round (blocking), and an agent can tell the tool apart without opening the schema.

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?

It states two explicit use cases ('look at a room before you join', 'see a round right now') and an explicit anti-pattern with the alternative: 'To wait for a result, call wait_for_round instead of calling this over and over.' Both when-to-use and when-not-to-use are covered.

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