vm_stats

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

The description includes a '[READ]' prefix, indicating it is read-only and safe, and mentions 'RRD-backed averages'. However, it lacks details on authorization requirements, error handling, or performance implications. Without annotations, the description partially fulfills transparency but has gaps.

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, well-structured, and front-loaded with the purpose. Every sentence adds value without redundancy, making it easy to parse quickly.

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 simple stats tool with no output schema, the description adequately covers inputs, behavior (read-only, RRD-backed), and parameter defaults. It does not explain return format or error cases, but given the tool's simplicity and low complexity, it is nearly 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?

The description explains all three parameters in detail: vm_id as 'VM uuid', granularity with allowed values and default, and target with context. Since the schema has no descriptions and 0% coverage, the description fully compensates and adds essential meaning.

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 it returns 'Recent CPU / memory stats for a VM' and labels it as a read operation. The purpose is specific and distinct from sibling tools like vm_get or vm_health_rca, though it does not explicitly differentiate them.

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?

No guidance is provided on when to use this tool versus alternatives, such as vm_get or vm_health_rca. The description implies it's for historical averages but does not offer explicit when-not-to-use or prerequisite information.

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