power_state

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

Annotations already declare readOnlyHint/idempotentHint and no destruction, and the description reinforces this with 'Changes nothing.' It goes further by disclosing return shape (powered_on bool, atx LEDs/buttons on PiKVM) and driver-dependent behavior (BMC/AMT answer from controller state), which matters because there is no output schema.

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-loads the one-line purpose, then return values, then when-to-use, then sibling routing. Every sentence carries distinct information with no restatement of the tool name.

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 read-only one-parameter tool with no output schema, the description covers purpose, return contents including device-family variance, and sibling routing—everything an agent needs to call it correctly and interpret the result.

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?

There is a single optional profile parameter whose schema description is fully covered (100%), so the schema carries the meaning. The description adds nothing about profile selection or defaults, which is acceptable at this coverage level but not additive.

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?

Opens with a specific verb and resource: 'Report whether the managed host is powered on (read-only).' It also names the return field (powered_on) and distinguishes itself from the mutating siblings power and wake by name.

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 trigger conditions: the cheap check after power/wake when their 'verified' came back null, and before deciding whether a dark snapshot means off or asleep. It also states the exclusions directly—use power to change power, wake to wake a sleeping host.

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