add_bill_entry

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

No annotations are provided, so the description carries the disclosure burden. It reveals meaningful behavior: the tax component routes to an ASSET account (input-tax credit) per taxtable, and how tax_included affects price extraction at posting. It does not disclose side effects or whether the operation is reversible, but for a line-item addition it covers the key behavioral nuance well.

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 well-organized with an Args block that is easy to parse, and front-loaded with the core action in the first sentence. Every parameter entry earns its place with format/semantic hints. Slightly longer than strictly minimal, but the tax and tax_included explanations are valuable and justify the length.

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?

This is a 9-parameter, 5-required mutation tool with 0% schema coverage and no annotations, so it needs substantial description. The description documents all parameters, key behavioral details (posting constraint, asset tax routing, gross/net handling), and even gives examples for required fields. An output schema exists, so return-format explanation is not needed. Minor gaps: no mention of validation errors or whether bill_id must be an existing bill, but overall strong coverage.

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, and it does: each of the 9 parameters is documented with format hints (decimal strings, examples like 'Expenses:Office Supplies', '000001') and semantic meaning (tax_included gross vs net, action as GnuCash line-type label). This goes well beyond the bare schema.

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+resource ('Add a line item to a vendor bill') and clearly distinguishes the tool from its sibling add_invoice_entry / add_credit_note_entry / add_voucher_entry by focusing on vendor bills. It also includes the prerequisite that the bill must not be posted yet, adding concrete scope.

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 clearly frames usage as adding line items to vendor bills and includes the 'must not be posted yet' constraint, giving practical context. However, it does not explicitly name alternatives or state when not to use it (e.g., for inventory items vs expense lines), so it lacks an explicit exclusion or alternative-pointer.

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