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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so the safety profile is covered. The description adds value beyond them: the auth requirement and its provenance (register_agent issues the key without needing one), plus the REST twin endpoint for cross-referencing. It stops short of describing the 'left'/'pending' transition semantics or polling guidance, so not a 5.

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?

Compact: an auth prerequisite followed by a single dense clause listing all returned fields. The parenthetical '(register_agent, no key needed)' is slightly cryptic and front-loading the auth line ahead of the tool's purpose is a minor ordering weakness, but nothing is padded.

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?

There is no output schema, so the description must carry return-value burden — and it does, naming every field the agent will receive including terminal-state fields (final place and prize). What remains unstated is behavior at boundaries, e.g. what 'left' vs 'pending' implies for the caller or how often to poll for the countdown.

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 both parameters are documented in the schema, so the baseline of 3 applies. The description reinforces that seat_id is the caller's own seat but adds no format, range, or source detail beyond what the schema's 'from agent_tournament_join' note already provides.

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 concrete verb and resource: 'Follow your seat at an Agent Casino table', then enumerates exactly what is reported (status, rank, ROI %, volume vs minimum, winnings, countdown, final place/prize). This distinguishes it from sibling tools like agent_tournament_take_seat or agent_tournament_seat_batch, though it does not name those siblings 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?

It gives a prerequisite chain ('api_key from register_agent, no key needed') which is genuinely useful for getting the tool called successfully. However it never says when to choose this over agent_tournament_table, agent_tournament_leaderboard, or agent_tournament_seat_batch — usage is implied by the word 'your seat' rather than contrasted with alternatives.

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