youtube_set_default_account

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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It states that a default is chosen, implying persistence and effect on subsequent calls, but it does not mention prerequisites (e.g., accounts must already be authorized), whether this overwrites an existing default, or if changes are reversible. Such gaps are critical for a mutation tool.

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, well-structured sentence that fronts the verb and the core concept. There is no fluff or repetition; every word earns its place, achieving maximum conciseness while preserving clarity.

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?

The tool is simple (one parameter, no output schema), but the description is still incomplete. It fails to specify how the agent should obtain a valid alias, whether the alias must correspond to an already-authorized account, or any side effects of making a call without setting a default. An agent cannot reliably call this tool correctly based solely on this description.

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 schema description coverage at 0%, the description must explain the 'alias' parameter. It only implies that alias is the name of an authorized channel ('which authorized channel calls use... when none is named'), but it does not define what an alias is, how to obtain one, or the expected format. This is insufficient for an agent to correctly supply the parameter.

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 (choose) and the resource (default authorized channel) and the conditional context (when none is named). It distinguishes this tool from siblings like youtube_accounts (lists accounts) and youtube_authorize (adds accounts), leaving no ambiguity about what it 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 phrase 'when none is named' implies a usage context but does not explicitly contrast with per-call account naming or mention when you would need to set a default. It offers no guidance on when to use this tool versus naming an account directly in other calls, leaving the agent to infer the intended workflow.

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