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

Beyond the annotations, it discloses critical side effects: draft does not post to the ledger, ready finalizes and affects the books, and MyInvois VALIDATE submits to LHDN and 'cannot be taken back.' It also explains conditional requirements for payment_mode and myinvois_action.

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 and well structured: WRITE first, then status effects, payment dependencies, MyInvois requirements, lookup guidance, and endpoint. Every sentence adds relevant 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?

For a 16-parameter create tool, the description covers the most important behavioral and conditional requirements. It does not describe the response or duplicate-prevention behavior, but the rich schema and annotations cover much of the remaining detail.

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 high at 81%, so many parameters are already documented. The description adds important conditional semantics for status, payment_mode, and myinvois_action, plus guidance to look up contact, account, term, and tax code ids first.

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 specific verb and resource: 'WRITE: create a sales invoice for a customer.' It clearly distinguishes creation from sibling read/list tools such as bukku_list_sales_invoices and bukku_get_sales_document.

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 gives clear usage context: status draft vs ready, payment_mode credit/cash dependencies, and when myinvois_action is required. It does not name alternatives or explicitly say when not to use this tool, but the write/create context is clear.

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