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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds meaningful traits beyond them: a real TLS handshake with no cache, and an explicit limitation that auto-renew status is not retrievable. This is genuine behavioral context, though it says nothing about failure/timeout behavior.

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 tightly-packed sentences with the core scope front-loaded ('live prüfen') and the key limitation last. No filler or repetition.

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 status check with full schema coverage and annotations covering the safety profile, this is complete. It even describes the return content (issuer, SANs, validity) despite having no output schema, and sets correct expectations about the auto-renew limitation.

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% and the single 'domain' parameter is fully documented in the schema (including the example.com example). The description adds no format or syntax detail beyond what the schema already provides, so the 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 and resource ('SSL-Zertifikatsstatus einer Domain live prüfen') and enumerates the returned content (Aussteller, SANs, verbleibende Gültigkeit). It clearly distinguishes itself from siblings like create_ssl_certificate or get_dns_security by being a live read of an existing certificate.

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 gives clear context for use (live status check of an existing certificate) and adds a useful boundary — that auto-renew configuration cannot be determined — which steers the agent away from expecting that from this tool. It does not, however, name specific alternative tools for those other needs.

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