Verify credentials and upstream reachability

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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint. The description reinforces the read-only nature ('Read-only; never returns the credential itself') and adds behavioral detail: it resolves the credential, makes one authenticated request, and reports specific diagnostic outputs. This goes beyond the annotations by describing the internal steps and the safety guarantee, which is valuable.

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 efficient and front-loaded: it starts with the core action, then lists the reports, then gives a safety note, and ends with usage guidance. Every sentence adds value with no redundancy. It is well-structured for quick parsing.

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 simple tool with no parameters and no output schema, the description covers all necessary aspects: what it does, what it reports, when to use it, and a safety guarantee. An agent can invoke it correctly and understand its results without missing information.

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 trivially complete (100% coverage). Since there are no parameters, the description does not need to explain parameter semantics. It correctly focuses on behavior and output, which is appropriate for a no-argument tool.

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 verb and resource: it resolves credentials and makes an authenticated request to canvas, reporting diagnostic details. It clearly distinguishes itself from sibling list/get tools by being a healthcheck, and names the exact output categories (source, acceptance, RTT, hint).

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 gives an explicit trigger condition: 'Call this when a real tool fails and you want to know which hop broke.' This is clear context for when to use it. However, it does not explicitly state when not to use it or mention alternatives, though none exist among siblings. The guidance is adequate but not exhaustive.

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