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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds substantive behavioral context by enumerating the diagnostics returned (adapter staleness, cache size, registry deployment, active network), which is the kind of detail an agent needs and annotations cannot express.

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?

Two sentences, front-loaded with the purpose followed by the payload enumeration and the diagnostic use case. The long parenthetical adapter list is dense but each item carries real information; little waste.

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 no output schema, the description takes on the burden of describing returns and does so thoroughly across five diagnostic dimensions, plus a stated diagnostic purpose. It does not mention auth/permission prerequisites, a minor gap for a read-only health probe.

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 tool takes zero parameters, so there is nothing to disambiguate; baseline for a 0-param tool is 4. The description correctly implies no input is required.

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?

States a specific verb+resource ('Report CaptureVerifier health') and then enumerates exactly what is reported: loaded adapters, staleness, challenge cache size, CaptureClassRegistry deployment, and active PCC_NETWORK. This clearly distinguishes it from siblings like pcc_capture_status or pcc_capture_class_registry.

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?

Explicitly gives a use case: 'Use this to diagnose why a capture class is being rejected or degraded.' That is a clear triggering context, but it names no alternative diagnostic tools and gives no exclusions (e.g., when to prefer pcc_capture_status).

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