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

Annotations declare readOnlyHint and openWorldHint, and the description adds genuinely useful behavioral detail beyond them: it performs a HEAD request, validates chain trust and hostname matching, and returns response time. It stops short of noting timeouts, rate limits, or that failures are reported rather than thrown.

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?

One sentence, front-loaded with the action and the reported result. No filler or redundancy.

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 single-parameter read-only check with no output schema, the description explains both the mechanism and what is reported. Minor gap: it doesn't state what happens on failure (error vs. negative report) or any timeout behavior.

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 description coverage is 100% and the single parameter is fully documented in the schema ('Bare hostname, e.g. example.com'). The description adds no syntax or format detail beyond that, so baseline 3 applies.

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?

States a specific verb+resource ('Attempt an HTTPS HEAD request to a hostname') and the exact output signal ('whether the TLS handshake succeeded... with response time'). An agent can distinguish this from check_url_status or trace_redirects without opening a schema.

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?

No guidance on when to use this versus siblings such as check_url_status or scan_security_headers, and no stated prerequisites (e.g. network reachability, that it does not follow redirects). The purpose is implied by the name, but no explicit when/when-not is given.

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