Get YouTube transcript

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

Annotations only declare readOnlyHint and openWorldHint, so the description adds meaningful behavioral context: it returns the video's spoken language by default and falls back to AI speech-to-text when captions are unavailable. This goes beyond the structured annotations and helps set expectations about the transcript source.

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 with no redundant content. The core purpose is front-loaded, and each sentence adds distinct value: input formats, output default, fallback behavior, and parameter use case. Nothing could be removed without losing useful information.

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 tool's simplicity, four parameters, read-only annotations, and full schema coverage, the description covers the essential context an agent needs to call the tool correctly. It could mention edge cases like invalid IDs or how errors are surfaced, but these are minor gaps for a read-only transcript fetch tool.

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 100%, so the baseline is 3. The description adds extra nuance not fully captured by the schema: it clarifies accepted URL variants for the video parameter and explains the default language behavior. The format guidance ('timestamped when you need to cite or jump to specific moments') also adds practical parameter semantics.

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: getting the transcript of a YouTube video. It enumerates accepted input formats (watch, youtu.be, shorts, embed URLs or 11-character IDs) and states the default behavior (spoken language), making the tool's purpose unambiguous even without sibling tools.

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 gives clear context for when to use the tool: whenever a YouTube transcript is needed. It also provides format-level guidance ('Use format=timestamped when you need to cite or jump to specific moments'), though it does not explicitly discuss alternatives or when not to use the tool, which is less necessary given there are no siblings.

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