Connect a YouTube channel

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

Beyond the annotations, it discloses the behaviors an agent could not otherwise infer: that a browser on the server host opens a Google consent screen, that a human must sign in and choose the channel or Brand Account, and that tokens are encrypted at rest and never returned. This makes clear the call is interactive and requires a user present, which matters greatly for a non-idempotent, open-world tool. Note the "read-only permissions" line refers to the granted Google scopes, not to tool behavior, so it does not genuinely contradict destructiveHint=true — though the pairing could briefly confuse a reader.

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?

Front-loaded with the action and auth method, then the mechanics, then the repeat-use note; each sentence adds something. Slightly long for a no-parameter tool, but no sentence is filler.

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 an interactive OAuth flow, the description covers the essentials: browser requirement, human interaction, token handling, and repeat use; an output schema exists so return values need not be described. It omits failure/cancellation behavior and any indication of whether an already-connected channel is duplicated or skipped, which is the main remaining gap.

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 zero parameters, there is nothing for the schema to describe, and the description usefully explains that channel selection happens inside the browser consent screen rather than through arguments. That is a meaningful clarification, though it does not say what happens if no channel is chosen or if the account is already connected.

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?

States a specific verb and resource ("Connect a YouTube channel") plus the mechanism (Google sign-in / OAuth 2.0), which cleanly separates it from sibling connect-adjacent tools like youtube_list_channels and youtube_disconnect_channel. It also clarifies that repeat calls add more channels rather than replacing the connection.

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?

"Call again to connect additional channels" gives explicit guidance on repeated invocation, and the browser/consent flow makes the context of use clear. It never names a sibling alternative (e.g., use youtube_list_channels to see what is already connected, or youtube_disconnect_channel to undo), so the routing guidance stops short of explicit alternatives or when-not-to-use.

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