Diagnose connectivity (why can't I reach X)

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

Annotations already indicate read-only, open-world, and idempotent behavior. The description adds valuable context by detailing the multi-step diagnostic process (DNS, ping, TCP, TLS, HTTP) and the verdict output, going beyond what annotations provide.

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?

Single sentence that is front-loaded with the core purpose ('One-shot diagnosis') and efficiently lists all performed checks. No unnecessary words.

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?

Given the tool complexity and absence of an output schema, the description adequately outlines the multi-step diagnosis and the nature of the result ('verdict on where the failure is'). However, it could mention what happens on errors or timeout.

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?

With 100% schema coverage and a single parameter described clearly as 'hostname or URL to diagnose', the description adds no additional meaning beyond the schema. Baseline score is appropriate.

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 clearly identifies the tool as a one-shot diagnosis that performs multiple checks (DNS, ping, TCP, TLS, HTTP) and returns a verdict, distinguishing it from specific sibling tools like dns_lookup or http_probe.

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 implies use as a comprehensive diagnostic but does not explicitly state when to use this tool instead of more specific siblings, nor does it mention any prerequisites or exclusions.

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