Start or stop a headless playtest

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

Annotations only say openWorldHint=false and destructiveHint=true; the description adds far more: the browser is the sole process started, it is recorded in .rpgmaker-mcp/session.json, and `stop` kills only that pid's tree after confirming the recorded profile directory is still on its command line. It also discloses the Allow Eval / keepAwake prerequisites and their failure modes.

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-loaded with the primary `start` behavior and action list before the edge cases. It is long and dense for a single paragraph, but nearly every clause carries operational value, so the size is largely earned.

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?

No output schema exists and this is a stateful, destructive-capable session tool, yet the description covers start/stop lifecycle, prerequisites, session-file tracking, refusal behavior, and action semantics. An agent has enough to call it correctly without opening other docs.

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 86%, so the schema already documents most parameters; the description still adds real meaning by explaining the newGame default walk, the 60-second call-budget interaction with boot, and why force exists. This goes beyond the schema text rather than merely restating it.

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 set and resource: it 'owns the whole loop' and enumerates each action (start/boot/status/reload/stop) with what each does. It explicitly distinguishes itself from siblings by saying live_status / live_screenshot / assert_in_game need a game that this tool provides.

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 and alternatives: pass newGame:false and call `boot` afterwards under a 60s-per-call client, use `reload` for a freshly written plugin file, `boot` alone to drive to a map. It also states the refusal condition (won't start a second browser while a game is reporting).

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