vm_stats

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

No annotations are provided, so the description must fully disclose behavior. It indicates read-only operation with '[READ]' and explains data source (RRD-backed averages). However, it does not mention return format, error cases, or limitations like potential staleness.

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 concise, using a single header line and a bullet-style args list. Every sentence adds value without redundancy. It is well-structured and easy to parse.

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?

The tool has moderate complexity (3 params, no output schema). The description covers purpose and parameters well but omits the output format and potential errors. For a stats tool, describing the return structure would improve completeness.

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?

With 0% schema description coverage, the description adds critical meaning: vm_id is specified as a VM UUID with reference to vm_list, granularity describes allowed values and default, and target explains its source and optional nature. This fully compensates for the schema's lack of detail.

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 starts with '[READ] Recent CPU / memory stats for a VM (RRD-backed averages)', clearly specifying the action, resource, and data type. It distinguishes from sibling tools like vm_list and vm_get by focusing on performance statistics.

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?

Description explains when to use the tool (to get recent CPU/memory stats) but does not explicitly contrast with alternatives such as vm_health_rca. The implied usage is clear but lacks a direct 'when not to use' statement.

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