hostname_history

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is fully covered. The description adds useful scope by stating what data is retrieved, but does not disclose auth needs, rate limits, or error behavior beyond what annotations provide.

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 short sentence with no wasted words, and the key information is front-loaded. However, it is a grammatical fragment rather than a complete sentence, which slightly reduces structural clarity.

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 a complete input schema, rich annotations, and an output schema, the description only needs to establish purpose and scope. It does that adequately for a simple lookup tool, though it could better situate itself among the related sibling tools.

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 the hostname and response_format parameters are already well documented by the input schema. The description adds no additional meaning about parameter usage or formatting, so the baseline score of 3 is appropriate.

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 clearly identifies the resource (one hostname's certificate history) and the data returned: first/last issuance, count, and issuers. It is more specific than a tautology, but lacks an explicit verb and does not distinguish itself from sibling tools like subdomain_timeline or watch_domains.

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 offers no when-to-use guidance, no exclusions, and no mention of alternatives among the sibling tools. An agent must infer the appropriate context solely from the stated purpose.

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