Verify credentials and upstream reachability

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

Annotations already cover read-only/idempotent/open-world, and the description adds real behavioral value: it resolves the credential exactly like real tools, makes exactly one authenticated request, never returns the credential, and tells the agent the three possible failure classes plus round-trip time. This is more than the annotations imply.

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 first sentence establishes mechanism, the second details outputs and safety, and the third gives the call condition. Dense but focused, with no filler or repetition.

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 tool with no output schema, the description fully covers invocation trigger, behavior, output categories, and safety. An agent can decide to call it and interpret results without further clarification.

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?

There are zero parameters, so the schema already fully covers parameter semantics. The description doesn't need to add parameter meaning, and the baseline for zero params 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 verb ('Resolves', 'makes one authenticated request', 'Reports') and exact resource (clientsecure.me), and explains the tool's diagnostic purpose. It is clearly distinct from the operating siblings, which are all individual actions on billing/appointments/etc.

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 explicitly says when to call: 'when a real tool fails and you want to know which hop broke.' It doesn't spell out when not to call or name an alternative, but the diagnostic context is unambiguous for a healthcheck tool.

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