stop_vm

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

No annotations are provided, so the description must carry full weight. It discloses the critical behavioral trait that allocation and billing continue after stop, which is not obvious from the tool name alone. However, it does not mention side effects, prerequisites (e.g., VM must be running), or whether the operation is synchronous or asynchronous.

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 extremely concise: two sentences for the main behavior and a clean two-line parameter list. Every sentence contributes necessary information, with no redundancy or fluff.

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?

Given the output schema exists (so return values are documented elsewhere) and the tool is straightforward, the description covers the essential behavioral nuance (keeps allocation). It lacks mention of error conditions or asynchronous behavior, but for a simple stop operation, it is largely complete.

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 description coverage is 0%, so the description should compensate. It simply restates the parameter names ('resource_group' and 'vm_name') with trivial explanations ('Resource group name', 'Virtual machine name'). These add no meaning beyond what the parameter names already imply, thus the description fails to add value over 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?

The description clearly states the action ('Stop a virtual machine') and adds a key distinction: 'VM stays allocated, charges continue.' This differentiates it from sibling tools like deallocate_vm, which likely deallocates and stops billing. The verb-resource pairing and additional context make the purpose highly specific.

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 implicitely indicates usage when you want to stop a VM without deallocating, but it does not explicitly mention when not to use it (e.g., for deallocation) or list alternatives. The sibling tools include deallocate_vm, start_vm, and restart_vm, but no guidance is provided for choosing among them.

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