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

The annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered by structured data. The description adds that expiry and validity are the data points of interest, but says nothing about whether it performs a live TLS handshake, how timeouts or connection failures surface, or how chain/hostname-mismatch errors are reported.

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 short sentences, zero filler. The what (expiry/validity) is front-loaded and the diagnostic purpose follows immediately.

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 an output schema present, return-value explanation is not required, and annotations cover safety. However, for a network-probing cert check the description is silent on probing behavior and failure modes, and the one undocumented parameter (port) is left to its default alone.

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 67%: hostname has an example and context_id is documented in the schema, while port is undocumented except for its default of 443 and 1-65535 bounds. The description's 'hostname:port' phrasing implies the port is a target selector defaulting to standard HTTPS, adding only marginal meaning beyond 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?

States a specific resource and what is returned: 'Certificate expiry and validity for a hostname:port.' An agent can distinguish this from Cloudflare-specific siblings like cf_ssl_verification or cf_ssl_certificate_packs because the scope is an arbitrary host:port, though the description never names those siblings to make the distinction explicit.

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?

'Use to rule out cert-expired as cause of outage' gives a clear triggering context during incident triage. It stops short of stating when NOT to use it or pointing to the alternative generic TLS/DNS checks (cf_ssl_verification, dnssec_check, tcp_connect) that an agent could confuse it with.

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