YouTube Transcript MCP Server

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

No annotations are provided, so the description carries full burden for behavioral disclosure. While 'Extract transcript' implies a read operation, it doesn't mention potential limitations like availability of transcripts (some videos may not have them), authentication requirements, rate limits, or error handling. The description is minimal and lacks crucial operational context.

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, efficient sentence that directly states the tool's function without any wasted words. It's appropriately sized and front-loaded, making it easy to parse quickly. Every word earns its place in conveying the core purpose.

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?

For a tool with 3 parameters, no annotations, and no output schema, the description is inadequate. It doesn't explain what the tool returns (transcript content, error messages, etc.), doesn't mention behavioral constraints, and provides no usage context relative to sibling tools. The description leaves too many unanswered questions for effective tool selection and invocation.

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%, with all parameters well-documented in the schema itself. The description adds no additional parameter information beyond what's already in the schema (e.g., it doesn't clarify URL formats beyond what's in the schema description, or explain language/format choices). Baseline score of 3 is appropriate when the schema does the heavy lifting.

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 action ('Extract transcript') and target resource ('from a YouTube video URL'), making the purpose immediately understandable. However, it doesn't differentiate this tool from its siblings like 'youtube_batch_transcripts' or 'youtube_get_channel_transcripts', which also extract transcripts but from different sources or in different modes.

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 provides no guidance on when to use this tool versus alternatives. With multiple sibling tools for transcript extraction (e.g., 'youtube_batch_transcripts' for multiple videos, 'youtube_get_channel_transcripts' for channel-wide extraction), there's no indication of when this single-video extraction is preferred or what its limitations might be.

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