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

Beyond the annotations it discloses meaningful behavior: the app restarts on the new bundle, up to 3 throwing boots trigger an automatic rollback to the old release, state is reverted with reason crash_loop, and the action is simulated and written to device_log. These are exactly the side effects an agent could not infer from readOnlyHint=false / destructiveHint=false.

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?

Three dense clauses, front-loaded with the action, then rollback semantics, then the failure condition. No filler; every clause carries information an agent needs.

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 mutating tool with no output schema, the description covers the effect, the automatic recovery path, the error case, and the logging destination — an agent can call it and interpret outcomes without further documentation.

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% and the single 'session' parameter is fully documented as coming from open_app, so the schema carries the load. The description adds nothing about the session parameter itself, which is acceptable but yields the baseline score.

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?

The description opens with a specific verb+resource ('Apply the ready release') and immediately anchors it to a known sibling ('like restart'), so an agent knows exactly what operation occurs. It also ties the tool to the update-state vocabulary ('unless the state is ready'), distinguishing it from check_for_update/get_update_state.

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?

It states a hard precondition — the state must be 'ready' or the call fails with not_ready — which implicitly routes the agent to the state-checking siblings first. It stops short of naming those siblings or saying explicitly when not to use apply_update versus restart.

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