check_tls

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

With no annotations, the description fully carries the burden of disclosing behavior. It clearly states that the tool performs a read-only inspection and lists the exact data points returned (validity, expiry, issuer, key strength, chain missing intermediates, TLS versions). This gives an agent a precise model of what will happen and what results to expect, with no unstated side effects.

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?

The description is concise and well-structured: the first sentence states the purpose and scope with a list of details, and the second sentence gives usage guidance. Every word earns its place, with no redundancy or filler.

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?

Despite having no output schema and no annotations, the description is complete for this simple tool. It explicitly enumerates the return-relevant data (certificate validity/expiry, issuer, key strength, chain, TLS versions) and provides enough context for an agent to decide when and how to invoke it. The single parameter is well-documented in the schema, and the description fills any gaps about the tool's behavior.

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?

The input schema has 100% coverage: the `domain` parameter is described as 'The domain to check, e.g. example.com. Do not include a scheme or path.' The tool description adds no further parameter semantics, so the baseline score of 3 applies—the schema already provides the necessary meaning.

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?

The description uses a specific verb ('Inspect') and resource ('domain's TLS configuration'), and enumerates exactly what is inspected (certificate validity, issuer, key strength, chain, TLS versions). This clearly distinguishes it from sibling tools like scan_domain and analyse_spf, which target broader or different concerns.

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 provides explicit use cases ('Use this for certificate problems, expiry checks...') and even mentions a subtle real-world scenario (works in browsers but fails in curl). It lacks explicit alternatives or when-not-to-use instructions, but the use-case list is sufficiently clear and targeted, so this is not a major gap.

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