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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so safety is covered. The description adds real behavioral detail beyond that: the 14-day expiry window used for flagging, the specific failure classes detected, and the rule about not writing a finding for fully unreachable hosts.

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?

Two tight sentences, front-loaded with the core purpose and detection list, followed by one clarifying exclusion. No filler or repetition of the tool name.

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 burden of explaining results, and it does describe what findings are produced (and the one case where none is produced). It does not describe output format or result shape, but for a diagnostic check whose annotations confirm a safe read, this is largely sufficient.

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?

Schema coverage is 50%: the required 'domain' param is documented in the schema, and the optional 'outputFormat' enum is self-describing via its enum values. The description adds no parameter-level information (formatting behavior, accepted domain forms), so it does not compensate for the remaining coverage gap. Baseline 3 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 names a specific verb (check) and resource (publisher domain HTTPS/certificate) and enumerates exactly which conditions it detects: expired/untrusted/hostname-mismatch certs, HTTPS down, non-upgrading HTTP, and certs expiring within 14 days. This makes it clearly distinguishable from sibling checks like check_crawler_blocks.

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 clear operational scope, including an explicit negative condition ('Does not write a finding when both HTTP and HTTPS are unreachable'), which tells the agent when the tool returns nothing. However, it names no alternative tool or the broader workflow context in which a domain check belongs.

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