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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint, so the safety profile is covered. The description adds the useful fact that no auth is needed and that a certificate chain is retrieved, but says nothing about failure behavior (expired/self-signed/invalid certs), timeouts, or rate limits for an open-world network call.

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 sentences, front-loaded with the core action, then the concrete set of inspected attributes. No filler or redundancy.

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, listing the inspected fields compensates well for what a caller should expect back, and the auth note removes a common uncertainty. It falls short only on edge-case behavior — what happens for an unreachable host or an invalid certificate.

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?

Only one parameter exists and schema coverage is 100%, with the schema already giving the 'example.com (without protocol)' format hint. The description adds no further parameter meaning, 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 ('Inspect a TLS/SSL certificate for a hostname') and enumerates the returned facets (issuer, subject, validity dates, SAN list, key algorithm, chain). This clearly separates it from neighboring diagnostics like vs_dns_check and vs_website_check, which probe different aspects of a hostname.

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?

Usage is implied by the purpose — call it when you need certificate details for a hostname — but the description never names alternatives or states when not to use it (e.g. for DNS resolution use vs_dns_check, for HTTP reachability use vs_website_check). 'No authentication required' is the only contextual guidance offered.

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