perf_kvm_stat_report

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

With no annotations, the description carries the burden and does provide useful behavioral context: it states the required prerequisite ('Requires: perf kvm stat record'), the output shape (exit reason table with count, time, percentage), and interpretive behaviors. It does not explicitly mention permissions or side effects, but as a read-only analysis tool this is a reasonable disclosure.

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 compact and well-structured: it leads with purpose, then use case, then key parameters, then output and requirements. Every sentence contributes value; there is no redundancy or filler.

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 tool's complexity (21 parameters) and the presence of a complete input schema and output schema, the description adequately covers the core purpose, diagnostic use cases, key parameter meanings, output, and prerequisite. It could be slightly more complete by mentioning side-effect/permission details, but overall it provides enough context for correct selection and invocation.

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 100%, so the baseline is 3. The description goes beyond the schema by detailing sort key values ('sample', 'time', 'max', 'min'), giving an example exit type ('HLT'), and explaining the guest/host filter semantics. Not all 21 params are covered, but the most decision-relevant ones are enriched.

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 opens with a specific verb+resource pairing: 'KVM virtual machine exit analysis: shows VM exit reasons, counts, and time per exit type.' This clearly distinguishes the tool from the many perf sibling tools by stating exactly what it analyzes and what it reports.

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?

It gives explicit use guidance: 'Use this to diagnose virtualization overhead' and provides concrete diagnostic examples (HLT exits, I/O exits, EPT violations). It does not name alternative tools or state when not to use it, so it falls just short of a 5.

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