Switch the plan's active account

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

The description adds substantial behavior beyond annotations: it explains the 30-day switch budget, which account gets locked and until when, that switching back also counts, that Google Ads is unchanged, and that already-active accounts are a no-op. These details directly clarify the destructive and idempotent 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 dense but front-loaded with the key cost and effect, then states the gating conditions, then clarifies that no Google Ads change occurs. Every sentence carries necessary behavioral or usage information without 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 a no-output-schema mutation tool with one parameter, the description covers the essential side effects, preconditions, edge cases, and no-op behavior. An agent has enough information to decide when and how to invoke it safely.

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 the single customer_id parameter is already documented with format details and its source (list_accounts). The description does not add parameter-specific meaning beyond using customer_id as the target.

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 names the exact action: spending the plan's 30-day account switch on customer_id, making it active, and locking the least recently used active account. This is specific and distinguishable from sibling tools like list_accounts or account_overview.

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 explicitly states when to call: only after another tool returned 'Account switch:' and the user agreed, or 'Account choice:' and the user picked this account. It also clarifies that a first pick spends no switch and that already-active accounts are a no-op.

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