build_journal

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

Annotations already declare readOnlyHint=true and idempotentHint=true, but the description adds a genuinely useful behavioral fact: an unbalanced entry is refused before any charge, and the error reports the difference. That is real failure-mode disclosure beyond structured fields, though how the output file is delivered is left to the output schema.

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 text is short, but the inline JSON example is jammed into a prose paragraph and wraps awkwardly, making the entry shape harder to parse than a code block would be. The sentence 'Entries must balance: an unbalanced entry is refused before any charge, with the difference' ends on a dangling fragment.

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 9-parameter tool, the description covers only the entries payload; the required target_format and the seven formatting/accounting options that determine the generated file are unexplained, leaving an agent unable to construct a valid call without guessing. The existence of an output schema excuses it from explaining return values, but the input gaps remain severe.

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% across 9 parameters, and the description only explains `entries` (with its account/debit/credit/concept fields and optional number). The required `target_format` has no enum and no explanation of valid values, and a3_format, fiscal_year, company_code, account_split, decimal_comma, account_digits, and start_entry_number are entirely undocumented in both places.

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 states a concrete verb and resource: composing journal entries into an import file, with an inline example of the entry shape. It is clear what the tool produces, but it never distinguishes itself from siblings like convert_journal or validate_journal, so an agent must infer the boundary.

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?

Usage is only implied via the parenthetical '(e.g. from invoices or a payroll summary)', which hints at the upstream source of entries. There is no explicit statement of when to call build_journal versus convert_journal, validate_journal, or bank_to_journal, nor of any prerequisites.

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