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

The destructiveHint annotation signals a disruptive mutation, and the description adds genuinely non-redundant context: served workloads go offline, the action is reversible only via civo_start_instance, and the instance continues to incur billing. Idempotency and any confirmation/async behavior are not covered, so not a 5.

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 short sentences, each earning its place: action, consequence/recovery, and cost note, with the core operation front-loaded. No filler.

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 single-resource mutation with no output schema, the description covers the operation, its blast radius, recovery path, and billing implication, which is enough to call it correctly. It omits region scoping behavior despite region being a parameter, a minor gap.

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%, with instance_id and region both documented in the schema including the CIVO_REGION default fallback. The description adds no parameter-level detail beyond that, so the baseline 3 applies.

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 ('Power off one instance') and immediately contrasts the lifecycle operation with civo_start_instance, so an agent can distinguish it from civo_reboot_instance and civo_get_instance without opening a 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?

The description gives clear context for when this applies (you want the instance offline) and names the restoring alternative, civo_start_instance. It stops short of explicit when-not guidance (e.g., preferring reboot for a restart), which would be needed for a 5.

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