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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds the probed-backend enumeration, a useful behavioral detail, but says nothing about cost, latency, or what happens on a failed probe, so it earns only modest credit beyond annotations.

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 short, front-loaded clauses that state purpose immediately with no filler. The English/Korean duplication adds length that a monolingual reader does not need, slightly denting efficiency.

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 diagnostic tool with no output schema, the description is mostly sufficient but omits the shape of the result (e.g. per-backend status/error fields) that an agent would want to interpret the probe. Annotations cover the safety dimension, leaving this as the main remaining gap.

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 the schema carries no parameter semantics to clarify; the baseline for a parameterless tool is 4.

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 names a specific action ('self-probe status') and resource ('each Reach backend'), and enumerates the exact channels probed (web/github/youtube/reddit/twitter/rss/search), so an agent knows this is a diagnostics tool distinct from reach_read/reach_search. It does not, however, distinguish itself from overlapping status/health siblings like hq_health or server_status.

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?

There is no explicit guidance on when to call this versus the sibling health/status tools (hq_health, server_status) or when not to. Usage is only implied by the word 'doctor' and the status framing.

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