runtime_stop

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

Annotations already declare destructiveHint=true and idempotentHint=false, so the destructive profile is covered. The description adds the return contract ('Returns: exit code') and the lifecycle link to runtime_run, but does not say what happens to running sessions or whether the game state is lost.

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 terse sentences, action first and return value second, with zero filler. Everything is front-loaded and nothing needs trimming.

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 simple terminate tool with a single optional parameter, the description covers the action, the creating sibling, and the return value in place of a missing output schema. Safety is carried by annotations, so the remaining gap is minor.

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 description coverage is 100% and the single optional session_id is fully documented in the schema, so baseline 3 applies. The description adds nothing about the parameter and does not clarify the multi-session case beyond what the schema already states.

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+resource ('Stop a game') and anchors it to the sibling that created it ('started with runtime_run'), so the agent knows exactly what this terminates. It does not differentiate itself from near-neighbors like runtime_pause or debug_terminate, which is the only thing keeping it off a 5.

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 'a game started with runtime_run' implies the precondition for use, but there is no explicit when-to-use vs when-not guidance and no mention of pause/terminate alternatives. Usage is inferable but not spelled out.

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