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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the two-valued return vocabulary (ok/degraded) and the failure-triage framing, but never explains what 'degraded' entails, which source is affected, or what an agent should do with a degraded result.

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 clauses, zero waste, and the output vocabulary is front-loaded before the usage trigger. Nothing repeats the title or annotations.

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 zero-parameter, no-output-schema health probe with read-only annotations, the description supplies what is needed to call it correctly. The only gap is guidance on interpreting or acting on a 'degraded' result, which an agent may need for follow-up decisions.

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 for the description to disambiguate; baseline 4 applies. The description correctly implies a parameterless global probe rather than a scoped query.

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?

Names a specific resource pair (source freshness and storage health) and even the return states (ok/degraded), which is more concrete than most get_* siblings. It stops short of an explicit verb, but 'health' as a zero-argument diagnostic read is unambiguous against siblings like get_state or get_signal_cards.

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?

'Call this when data looks stale or a call fails' gives a concrete trigger condition tied to observable symptoms, which is exactly what an agent needs to decide to invoke a diagnostic. No exclusions or alternatives are named, but no sibling competes for this role.

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