Verify this server can reach its upstream

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

Annotations cover the safety profile (readOnlyHint, idempotentHint, openWorldHint), and the description still adds substantial value: it enumerates the two distinct modes, the exact diagnostic fields returned (bridge role, port, version, link state, RTT), and explicit guarantees ("no auth required", "never returns the credential itself"). This is a genuinely helpful disclosure layer beyond the structured fields.

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 purpose and mode labels are front-loaded ("Relaying through your signed-in browser tab" / "Signing in server-side with configured credentials"), so the dense text is navigable. It is long, but nearly every clause adds a distinct diagnostic fact rather than restating structured data.

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 carries the full burden of explaining returns, and it does so thoroughly: it lists the diagnostic fields and the plain-English hint categories for both paths. An agent knows what it will get back and how to interpret each branch.

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 takes zero parameters, so per the rubric the baseline is 4 and there is no parameter syntax the description needs to compensate for. Nothing in the description muddies the parameterless contract.

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 opening sentence states a specific verb and outcome ("Reports which hop is broken when a real tool fails"), and the two paragraphs spell out exactly which connectivity paths are exercised. It is unambiguous what the tool does, though it never names the closest sibling (mah_auth_status) to differentiate itself explicitly.

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 trigger condition is clearly stated ("when a real tool fails"), which tells the agent exactly when to reach for it. What is missing is the when-not side and any explicit routing versus mah_auth_status, so it stops short of a 5.

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