List the brand’s own YouTube uploads

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

Annotations already mark readOnlyHint=true, so the description adds beyond that by revealing that unlisted and private videos are included, that it costs 0 credits, and that a connected YouTube channel is required. These are useful behavioral details not present in annotations, though not exhaustive.

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 front-loaded with the core purpose and return fields, then usage guidance, and finally differentiators. Each sentence contributes value and there is no fluff, though it is slightly longer than strictly necessary for the amount of unique 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?

For a read-only list tool with one optional parameter and no output schema, the description covers the key aspects: what is returned, when to use it, how it fits with other YouTube tools, and the caveat about unlisted/private videos. It lacks pagination or error details, but these are minor for such a simple 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?

The single parameter 'limit' has a schema description that fully covers it (default 25, max 50), providing 100% coverage. The tool description adds nothing about the parameter, so the schema carries the entire load. Baseline 3 is appropriate.

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 exactly what the tool does: lists the connected channel's own uploads with id, title, publish date, and privacy status. It explicitly differentiates from youtube_channel (counts only) and search_youtube (public index), making it unambiguous which tool to use.

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?

Provides explicit when-to-use instructions: call whenever the user names a video loosely and match it yourself, only ask when ambiguous. It also explains the tool's role as the source for videoId for other YouTube tools and contrasts with siblings, leaving no room for misinterpretation.

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