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

The description discloses important behavioral traits beyond the annotations: it is all-or-nothing (atomic), top-level transactionid links all records while per-item overrides, expense accountid can record a payment against a purchase document, and it returns the new ids. This adds substantial operational context not available from the annotations alone.

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 concise, using four sentences to cover the core purpose, usage guidance, key behavioral details, and return value. It is front-loaded with the primary purpose and avoids unnecessary fluff or repetition.

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?

Given the tool's complexity (nested income and expenses arrays with numerous fields) and the absence of an output schema, the description provides only high-level guidance. It covers atomicity, reconciliation, and payment behavior, but does not address many parameters like currency, amount, or supplier behavior, leaving gaps for an agent to infer from context.

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?

The description explains the top-level transactionid behavior and the special meaning of expense accountid, but does not elaborate on the income and expenses arrays or other parameters. Since the schema has 0% description coverage for the top-level parameters, the description only partially compensates; many parameters remain unexplained beyond their schema types.

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 tool's primary function: creating many income and expense records in one transaction. It explicitly distinguishes this tool from its siblings by stating 'prefer this over repeated save_income / save_expense calls', making the unique purpose unambiguous.

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 explicit guidance on when to use this tool ('prefer this over repeated save_income / save_expense calls') and when not to ('per-item salestax is not supported (use save_expense)'). This gives clear usage boundaries and alternative recommendations.

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