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

With no annotations, the description carries the full burden and does a good job: it discloses the read-only nature, that no API key or account is needed, and—unusually valuable—the exact cost model ($0.005/call via x402 USDC). It does not discuss rate limits, pagination, or failure behavior, so it falls short of a 5.

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?

Front-loaded with the core capability, then the ISSUED-vs-serving distinction, then cost—each sentence earns its place. Slightly long, and the pricing sentence could be tighter, but nothing is wasted.

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?

For a two-parameter lookup with no output schema, the description enumerates the returned fields and clarifies semantics of the data source, giving an agent everything needed to call it and interpret results correctly.

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 100%, so both parameters (domain, subdomains) are already fully documented, including host reduction and the default. The description adds no parameter-level detail beyond the schema, 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+resource: reads TLS certificates from Certificate Transparency logs, and enumerates exactly what is returned (issuer, validity window, days to expiry, revocation, hostnames). Crucially it distinguishes itself from a 'what is the server serving now' scanner, which separates it from siblings like red_domain_check or web_status.

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?

It gives a clear condition for when this is the right tool: finding certificates 'you did not know existed' versus checking live server state. However it never names an alternative sibling for the live-serving case, so routing is inferred rather than explicit.

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