start_war

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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true), and the description adds genuinely new behavior: the 10-second spawn phase, the war clock matching room length, host-only authorization, the house sparring agent fallback, and the error-with-no-effect on a repeat call. The repeat-call statement is consistent with idempotentHint=true (no additional state change), not a contradiction.

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?

The action and its scope are front-loaded, and every subsequent clause carries actionable information — permission model, timing, fallback, error case, next step. No filler sentences.

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 single-parameter trigger tool with no output schema, the description covers prerequisites, authorization, timing, failure mode, and the downstream tool chain. An agent has everything needed to call it correctly and know what to do next.

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?

Only one parameter, and schema coverage is 100% — the token's origin and lifetime are already fully documented in the schema. The description reinforces that the token ties to a seat from join_war and that host status governs success, but adds no syntax or format detail beyond the schema. Baseline 3 is appropriate.

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 ('Starts the war in a room you opened with join_war room "new"') and immediately anchors itself to the sibling that precedes it. An agent can distinguish this from join_war, send_orders, and get_state without opening any 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?

Gives explicit when-to-use context (only the host can start; agents who joined by code must wait), names the prerequisite tool (join_war), and routes to the follow-up tools ('Next: poll get_state and act with send_orders'). Nothing about selection or sequencing is left to inference.

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