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

Annotations already declare non-read-only, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds a genuine prerequisite the annotations cannot express – YouTube requires the person's own in-app consent the first time – which is exactly the kind of auth/permission context that earns credit. What happens when that consent is missing (error vs. silent no-op) is left unstated.

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?

Two sentences, front-loaded with the core action and followed by the account source and the one caveat. The parenthetical is slightly clunky but nothing is wasted.

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 two-parameter toggle with full schema coverage and no output schema, the definition gives enough to invoke it correctly, including the id source and the YouTube consent caveat. The one real gap is sibling disambiguation against set_auto_reply, which is not addressed.

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 coverage is 100% and both parameters are documented with clear meanings, including the boolean polarity. The description's note that account_id comes from get_auto_reply_settings merely repeats the schema's own parameter text, adding no new semantics; baseline 3 applies.

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 ('turns automatic replies on or off') and scopes it to one connected account, so the effect is unambiguous. It does not differentiate itself from the sibling set_auto_reply, which reads as a near-identical operation, leaving the agent to guess between them.

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?

It tells the agent where account_id comes from ('from get_auto_reply_settings'), which implies the natural read-then-write sequence. But there is no explicit when-to-use versus set_auto_reply, create_auto_reply_rule, or the draft-approval siblings, and no stated prerequisites or exclusions.

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