YouTube MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states this is a read operation ('Get'), but doesn't mention authentication requirements, rate limits, error conditions, or what happens with invalid URLs. For a tool with no annotation coverage, this leaves significant gaps in understanding its operational behavior.

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 appropriately sized with two sentences: one stating the purpose and returned data, another explaining the parameter. It's front-loaded with the core functionality. The Args section is clear but could be integrated more smoothly. There's minimal waste, though the example URL format adds helpful specificity.

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 has an output schema (which handles return values), no annotations, and a simple single-parameter input, the description is moderately complete. It covers the basic purpose and parameter meaning but lacks behavioral context (auth, errors, limits) and usage guidance relative to siblings. For a read-only tool with output schema, it meets minimum viability but has clear gaps.

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?

With 0% schema description coverage (the schema has no descriptions for parameters), the description provides essential semantic context for the single parameter. It explains that video_url should be a YouTube video URL and gives an example format. This compensates well for the schema's lack of documentation, though it could specify URL validation rules or accepted URL patterns more precisely.

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's purpose with a specific verb ('Get') and resource ('YouTube video'), listing the types of information returned (title, description, stats, tags, chapters). It distinguishes from siblings like get_channel_info or get_transcript by focusing on video metadata rather than channel data or transcript content. However, it doesn't explicitly contrast with search_videos, which might also return video information.

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. It doesn't mention when to choose get_video_info over search_videos for finding video details, or how it differs from get_channel_videos which might also provide video information in a list format. There are no prerequisites, exclusions, or context for usage relative to sibling tools.

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