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

Annotations only declare destructiveHint=true, so the description adds real value: it discloses the brief downtime, explains that hard mode is equivalent to pulling the plug and should be a last resort, and names the underlying API endpoints. It stops short of covering async behavior, idempotency, or auth requirements.

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 tight sentences; the destructive/last-resort caveat is front-loaded right after the default mode. The endpoint mapping is the only mildly extraneous detail and it is still relevant to the API context.

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, a 3-parameter tool, and full schema coverage, the description covers what an agent needs to act safely, including the downtime and mode tradeoff. It omits whether the reboot is asynchronous and whether the instance returns in the same state, which would fully close the loop.

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%, so the baseline is 3, but the description meaningfully enriches the enum beyond the schema's bare "soft (default) or hard" by explaining what each mode actually does to the machine. The region parameter is left entirely to the schema.

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 precise verb and resource with scope ("Reboot one instance"), and the soft/hard explanation makes the operation's nature unambiguous. An agent can distinguish this from the sibling start/stop tools without opening any schema.

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 conditional guidance for the mode ("soft (default)... hard... use only when soft does not work") and warns of downtime, but never says when to reboot versus stopping and starting, nor when to prefer a sibling tool. Usage is implied rather than routed.

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