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

With no annotations, the description carries the full burden. It discloses that the tool verifies the certificate chain and returns a verification status, and it explains why that matters ('an expiry date read off a certificate nobody checked proves nothing'). This is meaningful behavioral context beyond a simple read operation. It does not mention potential network delays or failure modes, but those are minor for this 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?

The description is a single, well-structured sentence that leads with the tool's core function and front-loads the most critical output fields. The appended rationale about chain verification earns its place by clarifying the behavioral intent. No wasted words.

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?

Given the tool's simplicity (two parameters, no output schema), the description covers the essential return values (issuer, validity window, days remaining, names, verification status). It does not mention error handling or edge cases, but for a straightforward certificate lookup, this is sufficient. The verification flag is a notable addition that completes the picture.

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 schema already provides descriptions for both parameters (hostname and port with default). The description does not add extra parameter-specific meaning, so it aligns with the baseline of 3 given 100% schema coverage. It implicitly suggests the hostname is the target, but that is already in 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?

The description states a specific verb ('presents') and resource ('TLS certificate'), and enumerates the key attributes returned (issuer, validity window, days remaining, covered names). It also includes a distinctive behavior (chain verification) that sets it apart from siblings like dns or ping, so an agent can easily tell what this tool does.

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 implies usage when certificate details are needed, but it does not explicitly compare with alternatives or state when not to use it. It mentions the verification aspect as a rationale, but lacks clear 'use this when...' or 'instead of...' guidance. This leaves some ambiguity for an agent deciding between cert and similar network tools.

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