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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the read-only safety is covered. The description adds the metered batch context, which hints at cost or rate limits, but does not disclose how the video batch is selected, error behavior, or response shape. It adds some value beyond annotations but lacks depth.

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?

Three sentences with no redundancy. The purpose is front-loaded, parameters are summarized in one sentence, and the metered note is brief. Every sentence earns its place.

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 that an output schema exists (so return format is covered), the description covers all parameter groups and flags the metered nature. It does not mention potential volume limits or that it processes multiple videos sequentially, but for a batch operation with an output schema, this is reasonably 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 coverage is only 20% (only 'channel' has a description), so the description must explain the other parameters. It explicitly names the choices: 'video count, ordering, language, and whether timestamped segments are included', mapping directly to video_limit, sort_by, language, and include_segments. This adds meaning beyond the bare schema, though it does not specify value ranges or defaults.

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 states a specific verb ('Fetch'), a clear resource ('transcripts for a selected batch of videos from a YouTube channel'), and distinguishes this from sibling tools like get_youtube_video_transcript by emphasizing the batch and channel scope. An agent can easily tell this is the channel-level batch operation.

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 implies the tool is for batch transcript retrieval from a channel but does not explicitly state when to prefer it over alternatives (e.g., for a single video use get_youtube_video_transcript) or when not to use it. The context is clear enough from the name and phrasing, but explicit routing is missing.

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