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

Goes well past the annotations (destructive, idempotent, openWorld) by naming exactly what is destroyed (chat history, AI messages) and who is affected (all participants disconnected). It adds two preconditions the annotations cannot express: the room must be live and non-host-moderated, and the caller must already be a participant agent — a bare roomId is insufficient. The reference to lock_pond sharing the same membership rule reinforces it.

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?

Front-loads the action and its consequences, then lays out the anti-use-case, the auto-cleanup alternative, and the preconditions in that order. Despite being several sentences, each one carries a distinct constraint (scope, prohibition, timing, live-room limit, membership requirement) with no filler.

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?

An output schema and full annotation set already cover return shape and safety profile, so the description's remaining burden is preconditions and side effects — both covered thoroughly (live/non-moderated room, participant membership, wipe scope, disconnect behavior). Nothing an agent needs to invoke it correctly is missing.

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%, so the baseline is 3; the description earns an extra point by clarifying that senderId is not just an identifier but a membership proof — the caller must have posted or drawn in the pond first, and a bare roomId will not satisfy it. It still says nothing about agentSecret behavior beyond what the schema already documents.

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 precise verb and resource — "End a live room session" — and immediately specifies the two concrete effects (disconnect all participants, wipe chat history and AI messages). It explicitly distinguishes itself from the delete-room interpretation, so an agent can separate it from siblings like create_pond or lock_pond without opening schemas.

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 an affirmative trigger ("Use when a pond must be force-emptied") and an explicit prohibition ("do NOT call it to 'delete' a room"), plus the reason: roomId stays a stable re-joinable door and an abandoned pond cleans itself in ~1h. It also routes the agent away by stating the automatic cleanup behavior, which is a genuine alternative to invoking the tool.

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