SSL/TLS certificate

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the fact that this is a live network fetch and that trust is evaluated rather than assumed, but it says nothing about handshake timeouts, error behavior on untrusted/expired certificates, or any rate limits — meaningful gaps for an open-world network tool.

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?

A single front-loaded sentence: verb and resource first, then the return contents. Every clause (issuer, validity, days left, SANs, trust, protocol) carries information an agent needs and nothing is padded.

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, enumerating the returned fields is genuinely useful and largely covers the response. However, the tool takes a port parameter whose semantics (default port, behavior on connection failure, what happens when the certificate is untrusted) are entirely unaddressed, leaving an agent unable to call it confidently outside the default case.

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 0%, so the description must compensate and does not: 'domain' is only inferable from the phrase 'for a domain', and the 'port' parameter is never mentioned at all, leaving the agent unaware that non-443 ports are supported or how the default is chosen.

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 opens with a specific verb and resource ('Fetch the live TLS certificate for a domain') and enumerates the exact fields returned (issuer, validity dates, days left, SANs, trust, protocol), which clearly separates it from siblings like dns_lookup or domain_lookup. It stops short of naming or contrasting with any sibling tool, so it is clear but not fully differentiated.

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?

There is no explicit when-to-use statement, no prerequisite, and no named alternative; the usage is only implied by the enumerated certificate fields. An agent can infer this is the tool for inspecting a live TLS certificate, but must guess whether it should prefer this over dns_lookup for any overlapping question.

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