Check if a URL is archived in the Wayback Machine and return the closest snapshot to a specified timestamp.
Check if a URL has been archived by the Wayback Machine and get the closest snapshot.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | URL to check for archived snapshots. | |
| timestamp | No | Target timestamp (YYYYMMDDhhmmss) for closest snapshot. |
Changes observed during successful MCP inspections.
v0.1.11Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare this as a read-only, idempotent, non-destructive open-world lookup. The description adds that it returns the closest snapshot, but it does not mention rate limits, failure behavior, authentication, or response details.
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 no wasted words. It communicates the core action and result compactly.
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 simple lookup with full parameter schema coverage and annotations, the description is mostly adequate. However, with no output schema it does not clarify what the returned snapshot contains, and it does not explain default timestamp behavior when omitted.
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?
The schema has 100% description coverage for both parameters. The description's phrase 'closest snapshot' lightly reinforces the timestamp parameter's purpose but adds no syntax or behavior beyond what the schema already documents.
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 a specific verb and resource: checking a URL against the Wayback Machine and retrieving the closest snapshot. It is understandable without opening the schema, but it does not explicitly distinguish itself from archive-related siblings such as archive_search or archive_metadata.
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 intended usage is implied by 'Check if a URL has been archived... and get the closest snapshot,' but there is no explicit guidance on when to use this versus archive_search/archive_metadata or when to omit the timestamp parameter.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.