check_smtp_tls

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

Clearly declares read-only behavior ('connects and quits without sending mail'), performance characteristic, and what it checks. No annotations provided, so description fully carries behavioral disclosure.

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?

No wasted words; all sentences informative. Front-loaded with main actions, followed by behavioral and usage details. Excellent structure.

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?

Although no output schema, description lists return values (cipher, cert SANs, expiry days, FCrDNS, STARTTLS flag). Covers live check nature, method, and use case comprehensively for a single-parameter tool.

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 has single parameter 'domain' with basic description. The tool description adds context that it queries all MX hosts for that domain, enhancing understanding beyond 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?

Description clearly states specific actions: live check of MX hosts, TCP 25, EHLO+STARTTLS, certificate validation, etc. Distinguishes from sibling tool 'check_mta_sts' for policy layer.

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?

Explicitly recommends pairing with check_mta_sts and mentions slower speed (10-30s). Does not list when not to use, but context clarifies its role for inbound TLS posture checking.

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