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

Annotations already cover readOnly and openWorld, and the description adds real value on top: it discloses that it connects only to the verified public IP (an SSRF-safety behavior an agent should know) and that the call is free. It stops short of describing failure modes, timeouts, or redirect/port handling.

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?

Three short sentences, front-loaded with the action and return payload, followed by the two constraint facts. No filler and nothing buried.

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 usefully enumerates what comes back and states the target restriction and cost, which is enough to invoke it correctly. Minor gaps remain around error behavior and non-standard ports, but nothing essential is missing for a one-parameter read 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 coverage is 100% and the single 'url' parameter is documented as 'Domain or https URL'. The description reinforces the constraint with 'public HTTPS host' but adds no format, normalization, or edge-case detail 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 verb and resource ('Read the TLS certificate of a public HTTPS host') and enumerates the returned fields (issuer, subject, validity dates, days left, SANs, protocol). This is unmistakably distinct from siblings like bursia_dns_records or bursia_security_headers.

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 target scope is clear ('public HTTPS host'), and 'Free' plus 'Connects to the verified public IP only' implies the intended safe, non-authenticated lookup use. However, it never says when to choose this over neighboring network-inspection tools or what to do for private/non-HTTPS hosts.

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