Transactions Create Transaction

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

Annotations already establish this is a mutation (readOnlyHint=false), non-idempotent, and open-world, so the bar for added context is low but the description barely clears it. It adds only the vague claim that the operation 'may create or update Monarch data' without explaining what triggers the update path or what side effects occur, such as balance updates via should_update_balance. No contradiction with annotations, but the added behavioral context is minimal and confusing.

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?

At two short sentences, the description wastes no words and front-loads the core purpose. However, the second sentence is vague filler that does not earn its place since it raises an ambiguity instead of resolving one.

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 non-read-only tool with 11 parameters, 5 required, and no output schema, the description is severely incomplete: no return-value information, no handling of duplicates or updates, no explanation of required inputs, and no guidance on how output_mode or fields shape the response. An agent cannot reliably construct a correct call from this definition alone.

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 schema description coverage at only 18%, nine of eleven parameters (including required amount, date, merchant_name, and category_id) are undocumented, and the description adds nothing about them. The description does not compensate for the schema gaps — a caller gets no help understanding owner_user_id, goal_id, fields, output_mode, or should_update_balance beyond their raw names.

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 ('Create transaction'), so it is not a tautology, and the name distinguishes it from transactions_update_transaction. However, the second sentence ('This may create or update Monarch data') introduces ambiguity about whether the tool creates, updates, or both, which muddies the stated purpose rather than clarifying it.

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?

No guidance is given for when to use this tool versus siblings such as transactions_update_transaction or transactions_delete_transaction. The 'may create or update' phrasing is the opposite of an exclusion — it never states the conditions under which an update occurs or when a caller should choose the dedicated update tool.

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