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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely new behavior: the answer comes from cached state plus fleet_status and the call has no side effect on vehicle wakefulness.

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 short sentences, the capability first and the non-waking guarantee second. Nothing is padded or repeated from the 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?

With no output schema, the description usefully spells out the return semantics (reachability plus fleet_status values). The only remaining gap is the vin parameter and behavior when it is absent, which is not addressed.

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 50%: 'simulate' is documented in the schema, but 'vin' carries no description anywhere. The description only hints at the target ('the connected car') without clarifying how vin selects the vehicle or what happens when it is omitted (required parameters = 0).

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 and resource ('reports whether the connected car is reachable'), enumerates the possible states (asleep, offline, unsupported), and closes with 'Does not count as a wake,' which cleanly separates it from the wake_vehicle sibling.

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 'Does not count as a wake' implicitly tells the agent to use this instead of wake_vehicle when it only needs a reachability check. It stops short of naming the alternative or stating exclusions explicitly, so it is clear but not fully routed.

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