Verify credentials and upstream reachability

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

The description goes well beyond the annotations. It discloses that the tool makes exactly one authenticated request (bounding the side-effect footprint), never returns the credential itself (privacy guarantee), and reports three distinct failure classes plus round-trip time. The read-only property is redundant with the annotation, but everything else adds genuinely new operational context.

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?

Four sentences, each earning its place: purpose, report shape, safety property, trigger condition — with the core action front-loaded. The only blemish is a minor grammar slip ('a api.resy.com-side problem').

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 inputs (none needed), behavior (credential resolution, one call, no credential leakage), outputs (source, acceptance, RTT, plain-English hint), and the trigger/timing for use. An agent can invoke this tool correctly with nothing further from the schema or annotations.

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 has zero parameters, so the schema carries no burden and the baseline is 4. The description compensates by explaining exactly what the tool does upon invocation — credential resolution, one upstream request, and a human-readable report — so an agent knows what the 'argument' to expect.

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 states a specific verifiable action — resolve the credential the way real tools do, then make one authenticated request to api.resy.com — and immediately differentiates it from the operational sibling tools, all of which perform actual booking/search/favorite actions. Reporting the credential source, acceptance status, RTT, and a three-way failure hint gives the tool a crisp, unambiguous diagnostic mission.

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 final sentence makes the trigger precise: 'Call this when a real tool fails and you want to know which hop broke.' This gives the agent a clear use-after-failure condition. It never names exclusions or alternative tools explicitly, but for a standalone healthcheck the context is sufficiently clear to route the agent correctly.

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