web_archive_fetch

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

With no annotations, the description must disclose behavioral traits. It mentions finding the 'closest' snapshot and optional text reading, but omits details on fallback behavior when no snapshot exists, rate limits, or API dependencies. This provides moderate transparency but with gaps.

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, front-loaded sentence that efficiently conveys the core purpose. It is concise and avoids redundancy, though it could be slightly more structured (e.g., separating the find and read actions) without significant bloat.

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?

Given the 4 parameters, no output schema, and no annotations, the description is incomplete. It does not explain what happens when no snapshot is found, the output format, or prerequisites like network access. Important behavioral and contextual details are missing for a tool of this complexity.

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 only 25% (only timestamp has a description). The tool description adds minimal semantic value beyond the schema, merely hinting at fetch_text via 'optionally read its text.' It does not sufficiently compensate for the low coverage in explaining url, lang, or the purpose of each parameter.

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 it finds the closest Wayback Machine snapshot of a URL, specifically for dead or changed sources, and optionally reads its text. This differentiates it from sibling tools like web_fetch or web_read that target live pages.

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 includes the context 'for dead or changed sources,' which indicates when to use this tool. However, it does not explicitly state when not to use it or list alternative tools, leaving some ambiguity.

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