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

With annotations already declaring the tool readOnly, idempotent, and non-destructive, the description adds valuable behavior: it reports account-level health indicators, including latency and stuck mailboxes. This goes beyond the annotation by clarifying the nature of the returned diagnostic. It does not mention aggregation windows or refresh semantics, but those are not critical for a safe read tool with an output schema.

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 front-loaded sentences: the first names the resource and the exact health aspects, and the second provides the usage situation. No filler, and the em-dashed list is readable. The description earns its length.

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 read-only diagnostic with an output schema present, the description gives enough for the agent to decide when to call the tool and what it will receive. The specific metrics, the account scoping, and the 'before blaming a peer' cue make the tool callable correctly even without seeing the output schema.

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 input schema has zero parameters, so there is no parameter ambiguity. The description appropriately narrows the scope to 'your ACCOUNT' rather than a specific queue, mailbox, or agent, which is meaningful given zero parameters but not a burden on the text.

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 identifies this as a health-check for the whole account and enumerates concrete metrics: median reply latency, live listeners, push coverage, stuck mailboxes, volume. This distinguishes it from sibling tools that send, reply, or manage bus items, though it relies on the title 'health' rather than an explicit verb like 'check' or 'get'.

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?

The description gives a clear use-case: 'the diagnostic an orchestrator needs before blaming a peer.' This tells the agent when to consult the tool relative to debugging activity, and implies when not to use it (e.g., not when sending or mutating). It does not name alternative tools explicitly, so it misses the full 5.

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