Verify credentials and upstream reachability

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

Annotations already mark it read-only and idempotent, but the description adds meaningful behavioral detail: it resolves the credential the same way real tools do, makes exactly one authenticated request, reports the credential source, round-trip time, and a plain-English failure hint, and never returns the credential itself. This goes well beyond the 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?

The description is compact yet information-dense, with the core behavior front-loaded and every sentence contributing either the action, the output details, the safety guarantee, or the usage trigger. No filler or redundant restatement of the title exists.

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?

With no output schema, the description fully explains what the tool reports: credential source, acceptance status, round-trip time, and a hint distinguishing failure modes. It also covers safety (read-only, no credential leakage) and the intended use case, making it complete for an agent to invoke correctly.

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 and the schema is empty, so there is no parameter ambiguity. Per the baseline for 0-parameter tools, the description does not need to compensate for missing schema information, and it appropriately focuses on behavior and output instead.

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 diagnostic purpose: resolving credentials, making one authenticated request to aeroapi.flightaware.com, and reporting whether the credential was accepted. It clearly distinguishes this healthcheck tool from the many data-fetching siblings by focusing on connectivity and credential validation rather than flight/airport data.

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 an explicit trigger: 'Call this when a real tool fails and you want to know which hop broke.' This tells an agent exactly when to use the tool and frames it as a diagnostic aid rather than a data source, which is sufficient given no sibling serves the same role.

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