Read a page as it was

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

Annotations already flag readOnly/openWorld/idempotent; the description adds the key behavioral fact that the answer always includes 'days_from_requested' and that the closest capture can be years away, urging the agent to read it before interpreting. It also explicitly states it does not return page contents, which is crucial for expectation setting. No contradiction.

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?

Four short sentences, each carrying essential information: purpose, usage, caveat, and limitation. No filler.

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 output schema available, annotations covering safety, and schema describing parameters, the description adds the critical caveat about date proximity and the non-content return. This is enough for an agent to invoke correctly and interpret the result. The tool's purpose and behavior are fully covered.

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 coverage is 100%, with detailed descriptions for both 'url' and 'at', including format and default behavior. The description repeats the 'at' advice but adds no new parameter meaning beyond the schema. Thus the schema carries the load; the description's contribution is minimal.

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 'Find the Wayback Machine capture of a web page closest to a given date' – a specific verb, resource, and scope. It further clarifies it links to the capture and does not return page contents, distinguishing it from sibling tools like search_inside or get_item. The purpose is unambiguous and distinctive.

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 gives explicit usage instructions: 'Give "at" to ask for a moment in time; leave it out for the most recent capture.' It also warns about interpreting 'days_from_requested'. However, it does not explicitly contrast with sibling tools or state when not to use it, though the purpose is distinctive enough to infer.

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