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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, but the description adds genuinely new behavioral facts: the URL is temporary, no binary data is pulled into the conversation, and no API key is required. It still omits how long the URL stays valid, which would matter for a temporary artifact.

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, front-loaded with the capability before the behavioral caveats, and no filler. The closing clause about the API key is the weakest sentence but still conveys auth context.

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?

An output schema exists, so return values need no explanation, and the description covers format, quality, fallback behavior and the no-binary-download guarantee. What is missing is the link to get_social_media_download_options for discovering supported options and any note on URL lifetime.

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 100%, so the schema already explains url, format, quality and audioBitrateKbps, including examples and ranges. The description only restates the format choice and adds the fallback rule, which is a modest supplement to an already-complete schema, so the baseline of 3 applies.

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?

States a specific verb (prepare) and resource (one temporary download URL) and scopes it to public YouTube, Instagram, or TikTok media, so the agent knows exactly what it produces. It does not distinguish itself from the sibling get_social_media_download_options, which is the most likely point of confusion, so it falls short of a 5.

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?

Usage is implied by the platform and format scoping, and the quality-fallback sentence tells the agent what happens when the exact quality is unavailable. However, there is no explicit when-to-use/when-not guidance and no pointer to the related get_social_media_download_options sibling for discovering valid options.

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