Read a page as it was

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

Beyond the annotations (readOnlyHint, idempotentHint), the description adds significant behavioral context: the response always includes 'days_from_requested', the URL can resolve to a neighboring form, and it does not return the page's contents. These are not in the annotations.

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 relatively long but front-loaded with the main purpose. Every sentence adds value, covering purpose, parameter usage, key caveats, and non-behavior, making it appropriately sized for the tool's complexity.

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 tool with only two parameters, an output schema, and strong annotations, the description is thorough: it explains the main purpose, parameter semantics, important behavioral nuances, and explicitly states what the tool does not do. No significant gaps remain.

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 already has 100% parameter coverage, and the description adds extra meaning by explaining how to use 'at' (omit for most recent) and that the URL may resolve to a neighboring form. This goes beyond the schema descriptions.

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 states the tool finds the Wayback Machine capture of a web page closest to a given date, using a specific verb and resource. It also differentiates from sibling tools by noting it links to the capture but does not return page contents.

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?

Provides clear guidance on when to use it (closest capture to a date) and explains the 'at' parameter's behavior, but does not explicitly name alternative tools for different needs, such as searching inside content.

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