ynab_update_transaction

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

Annotations already indicate it is a write operation (readOnlyHint=false), non-destructive, and idempotent. The description adds value by mentioning the dry_run parameter for previewing changes and stating the return value, which goes beyond annotations.

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-structured with a clear purpose sentence followed by a bullet-like parameter list. Each parameter earns its place, but some redundancy exists (e.g., 'optional' repeated). It is efficient without being overly verbose.

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 the tool's complexity (13 parameters) and the presence of an output schema, the description covers most expected aspects: parameter details, return value, and a preview feature. Minor gaps like missing account_id and flag_color are present, but overall it is fairly complete.

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?

With 0% schema description coverage, the description compensates by explaining 10 out of 13 parameters, including units (milliunits for amount), date format, alternative payee fields, and enum values for cleared. This provides meaningful context beyond the 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 clearly states the action ('Update fields') and the resource ('existing YNAB transaction') with a specific verb and resource. It distinguishes itself from sibling tools like ynab_create_transaction or ynab_delete_transaction by focusing on update.

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 does not provide any guidance on when to use this tool versus alternatives. It fails to mention that for bulk updates, one should use ynab_update_transactions, or any other context about when not to use it.

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