Get my channel

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds meaningful behavioral details: it returns specific channel metadata and reads the exact subscriber count, and it warns that omitting the account parameter when multiple channels are connected causes the call to fail and list choices. No contradiction with annotations.

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 two sentences, with the core purpose and return fields front-loaded, followed by the key differentiator. No filler or redundant repetition of the title or schema. Every sentence contributes essential 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 simple read-only tool with one optional parameter and no output schema, the description provides sufficient information: it lists the returned fields, the exactness of the subscriber count, and the account behavior. Given the annotations cover safety and idempotency, nothing critical is missing for an agent to call it correctly.

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%, so the parameter 'account' is already documented with its purpose and behavior. The description adds extra value by explicitly noting the failure mode when omitted and the selection behavior, which is not fully captured in the schema. This enhances the agent's understanding beyond the schema.

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 a specific verb ('get') and resource ('my channel'), enumerates the exact fields returned (subscribers, total views, video count, uploads playlist id), and explicitly contrasts with get_channel by highlighting the exact vs. rounded subscriber count. This leaves no ambiguity about what the tool does.

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 a clear differentiator from get_channel ('reads the exact subscriber count rather than YouTube's rounded public figure'), which implicitly tells an agent when to prefer this tool. However, it does not mention alternatives like get_channel_analytics or list_accounts, and does not explicitly state when not to use it, though the parameter description adds context about the account requirement.

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