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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety and idempotency profile is fully covered. The description adds the temporal-history scope but no extra behavioral context such as CT log latency, coverage of subdomains, or data freshness.

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 with the key resource first and the temporal detail after the colon. Slightly redundant, since 'certificate history' and 'when certificates were issued' restate the same idea, but overall efficient.

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?

The tool is simple (one obvious parameter), an output schema exists so return values need not be explained, and annotations cover the safety profile. The description gives enough for correct invocation, though it omits any hint of the difference from get_ct_certificates.

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 ('domain') with 0% schema description coverage, so the description must carry the meaning. It does implicitly convey that the input is a domain ('certificate history of a domain'), which matches the parameter name, but adds no format or scope detail (e.g., whether subdomains or URLs are accepted).

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 ('Get the certificate history of a domain from Certificate Transparency') and adds a scope qualifier about issuance and change times. It is clear what the tool returns, though it never names the closest sibling get_ct_certificates to disambiguate the two.

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 only implied: the emphasis on 'history', 'when issued' and 'when changed' suggests temporal/change-analysis use cases, but there is no explicit when-to-use statement, no exclusions, and no pointer to get_ct_certificates or get_ct_dns_records as alternatives.

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