grow_disk

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

Annotations already indicate a non-read-only, non-idempotent, non-destructive operation. The description adds useful context that growth is not destructive (contrasting with shrink), but does not disclose other behavioral traits like prerequisites (e.g., guest state) or reversibility. With annotations present, the bar is lower, so a 3 is appropriate.

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 succinct and well-structured, with a clear purpose statement and an Args block that adds necessary detail without redundancy. Every sentence earns its place.

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 an output schema present, return value explanation is unnecessary. The description covers purpose, scope, usage boundary, and argument semantics comprehensively. No critical information is missing for an operation of this complexity.

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 0%, so the description carries full burden. It explains each parameter clearly: vmid, disk with examples, and increment with format requirements ('+10G', must start with '+'). This fully compensates for the schema's lack of descriptions.

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?

Description clearly states 'Grow a guest disk' with a specific verb and resource, and explicitly differentiates from shrink_disk by saying 'Growth only'. This is unambiguous and distinguishes from siblings.

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 explicitly states when to use this tool vs alternative: 'Growth only — shrinking is destructive and lives in shrink_disk.' This provides a clear exclusion and names the alternative tool for shrinking.

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