update_transaction

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

Discloses dry_run behavior as 'Validate and preview without updating', default budget_id behavior, and that only provided fields are changed. No annotations provided, so description carries 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?

Well-structured with clear initial sentence, usage guideline, and arg list. Slightly long but no extraneous text; front-loaded with purpose.

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?

Covers all parameters, notes default budget, includes dry_run. Does not discuss error cases or return values (output schema present). Generally complete for a mutation tool with many optional fields.

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 0%, but the description adds clear meaning for each parameter (e.g., amount format, cleared values). Compensates fully for missing schema descriptions.

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?

Clearly states 'Update fields of an existing YNAB transaction' with verb+resource. Distinguishes from siblings like create/delete/update_scheduled implicitly, but not explicitly.

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?

Provides the guideline 'Only provide the fields you want to change.' Does not give explicit when-to-use vs. alternatives like create_transaction or update_scheduled_transaction.

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