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

Annotations already indicate readOnlyHint=true and destructiveHint=false. The description adds context about supported platforms and that no transcription/vision occurs. However, it does not disclose potential rate limits, authentication needs, or whether the output includes metadata, which would add value beyond 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?

Two sentences with no wasted words. The purpose is front-loaded, and the second sentence provides clear usage guidance. Highly efficient.

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?

No output schema exists, but the description mentions 'every video quality, audio track and image, with quality labels.' Still, the exact format of the response is unspecified, which may leave an agent uncertain about parsing. For a simple tool with one parameter, the description is decent but not fully complete.

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 0%, but the description explains that the 'url' parameter accepts TikTok/Instagram/YouTube links or direct .mp4/image URLs, adding significant meaning beyond the bare schema type definition.

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 resolves TikTok/Instagram/YouTube links or direct media URLs to direct download URLs with quality labels. It specifies the verb (resolve) and the resource (download URLs from source CDN) and distinguishes from siblings like socialdl_extract and socialdl_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 description explicitly says to use when the user wants to download/save media instead of transcribing it, and notes 'No transcription/vision.' This provides clear when-to-use and what-not-to-do, though no direct alternative sibling is named.

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