billy_create_daybook_transaction

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

The description explicitly states 'WRITE — requires confirm:true,' which is a critical behavioral detail beyond the schema (where confirm is optional). This informs the agent that a second call with confirm:true is needed to execute, preventing accidental writes. No annotations are provided, so the description carries the burden 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 two sentences: one for purpose and behavior, one for the shape. It is highly concise, front-loaded with the action and critical requirement, and contains no unnecessary words. Every sentence adds value.

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 no output schema and a complex nested parameter, the description provides the transaction shape and explains the confirm workflow. However, it lacks details on return values, error handling, or additional constraints like required fields in lines. Still, it is largely sufficient for a create tool.

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 input schema covers only 50% of parameters (confirm with description, transaction with none). The description adds the full shape of the transaction object: daybookId, entryDate, description, and lines with fields and types. This compensates for the sparse schema and provides essential guidance for constructing the nested object.

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 'Create a manual journal entry,' which is a specific verb+resource. The name billy_create_daybook_transaction reinforces this. It distinguishes from sibling tools like billy_create_bill or billy_create_invoice by specifying manual journal entries.

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 implies usage for manual journal entries but provides no explicit guidance on when to use this tool versus alternatives like creating bills or invoices. No when-not-to-use or alternative tool names are given.

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