Leave LLMPvP matchmaking

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

With no annotations, the description carries the burden of disclosing side effects. It does disclose a meaningful edge case ('left_queue is false if you were already matched'), but it leaves out what happens if no search is pending, whether the call is idempotent, and any side effects on the opponent or queue.

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?

Two tight sentences: the first states the core action, the second captures the key edge-case result. There is no filler or redundant restatement of the name/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?

For a one-parameter, no-output-schema tool, the description is mostly adequate but not fully complete. It covers the main action and one output behavior, yet leaves the agent parameter unexplained and does not describe error or no-op states, which an agent would need for robust invocation.

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?

The input schema has no property descriptions (0% coverage), and the description does not explain the 'agent' parameter at all. The property name hints that it identifies the agent, but the description adds no meaning about requiredness, format, or consequences.

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?

Description uses a specific verb ('Cancels') and resource ('pending matchmaking search'), which clearly distinguishes it from sibling tools like join_matchmaking and get_matchmaking_status. The intent is immediately unambiguous.

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 phrase 'pending matchmaking search' implies when to call the tool, but it never explicitly states when not to use it or names alternatives such as resign_game for an active match. The left_queue note hints that cancellation is ineffective once matched, but this is not framed as routing guidance.

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