billing_get_account_spend

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

Since no annotations are provided, the description bears the full burden. It proactively discloses the key behavioral distinction between lifetime and date-filtered spend, and mentions that spend is aggregated from insights. It doesn't cover error cases or currency, but the core behavior is transparent.

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 concise sentences, front-loaded with the action. No redundant text and every sentence adds meaningful behavioral 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?

No output schema or annotations exist, so the description must explain return behavior and parameters. It does explain the lifetime vs period return shapes, but it omits details about date_preset and does not describe the response structure beyond the field name 'amount_spent'. For a low-complexity tool, it's adequate but leaves gaps.

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 0%, so the description must compensate. It adds the high-level semantic of including or excluding date params, but it never names the specific parameters (since, until, date_preset) or explains their formats. The account_id parameter is also not described. This is helpful but incomplete.

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 uses a specific verb 'Get' with a clear resource 'total amount spent by an ad account'. This distinguishes it from sibling tools like billing_get_invoice (invoice details) and billing_summary_all_accounts (summary across accounts).

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 implicitly defines usage by explaining behavior: without date params it returns lifetime spend, with date params it aggregates spend for a period. It does not explicitly mention alternatives or exclusions, but the use case is clear and unambiguous.

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