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

The annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true), and the description is consistent with them by calling this a "live" handshake test. Beyond that, it discloses that the tool returns a 0-100 readiness score, Harvest-Now-Decrypt-Later risk, and findings, which an agent could not infer from the structured fields. It does not mention timeouts, rate limits, or whether redirects/SNI mismatches are followed, which leaves a modest gap.

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 dense but disciplined sentence: verb and resource first, then the checks performed, then the return values. Every clause maps to either a check the tool runs or an output it produces, with no filler.

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 describing returns, and it does so adequately by naming the score, risk rating, and findings. For a one-parameter read-only scan this is close to complete; only minor operational details (timeouts, handling of non-resolving hosts) are absent.

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 100% for the single parameter, so the schema already documents the domain/host:port format. The description adds meaning beyond the schema by constraining the target to a public domain, implying resolvability and external reachability requirements. That is a genuine semantic constraint not encoded in the schema.

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 gives a specific verb and resource ("Live TLS handshake test of a public domain") and then enumerates the concrete checks (X25519MLKEM768/SecP256r1MLKEM768 hybrid key exchange, TLS 1.3/1.2, legacy downgrade, certificate key, HSTS). This is unmistakable against the sibling tools, none of which touch TLS at all.

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 phrase "of a public domain" implicitly conveys the precondition that the target must be publicly reachable, which is real usage guidance. However, there is no explicit when-to-use/when-not guidance, no statement about internal or unresolvable hosts, and no named alternative. The usage context is implied rather than stated.

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