instance_update

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

With no annotations provided, the description must carry the full burden of disclosing side effects. It lists parameters and return type but does not state whether updates are immediate, if the instance is rebooted, if certain fields cannot be changed together, or if there are irreversible effects. For a mutation tool, this is a critical omission.

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?

The description is a structured list of arguments and returns, which is efficient and scannable. It front-loads the purpose and then lists each parameter with a short comment. It avoids redundancy, though slightly verbose with the explicit 'Args' and 'Returns' headers.

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?

While the parameter semantics are covered, the description lacks essential context for a 9-parameter update tool. It does not explain that only provided fields are updated (since all optional params default null), nor does it mention any constraints or side effects. Given the absence of an exposed output schema and the mutating nature of the tool, more guidance is needed.

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?

The schema has zero descriptions, so the parameter explanations in the description are essential. Each parameter gets a brief but helpful comment (e.g., 'New label for the instance'), and instance_id is clarified to accept an ID, label, or hostname. This adds meaningful value beyond the raw 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?

The description clearly states 'Update an existing instance' and enumerates the specific attributes that can be modified (label, tag, plan, etc.), distinguishing it from instance_create, instance_delete, instance_start, and other sibling tools. The verb-resource pairing is specific and unambiguous.

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?

There is no guidance on when to use this tool versus alternatives. It does not mention whether it should be used for config changes versus other operations, nor does it note prerequisites such as the instance needing to exist or be in a certain state. The description is purely a parameter listing without any contextual direction.

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