change_transaction_category

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

Annotations already indicate a destructive, non-read-only operation. The description adds a critical behavioral requirement: 'Codex must request user approval before calling this tool.' It also specifies 'one existing transaction,' implying the tool does not create transactions. This goes beyond the annotations by mandating an approval step.

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 concise sentences. The first states the core purpose, and the second is a direct approval directive. No wasted words; all content earns its place.

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?

The tool is simple with only two parameters and no output schema, but the description fails to define what 'category' means or that it should reference an existing category from list_categories. It also omits any details about return values or behavior on invalid inputs. Given the mutation risk and 0% schema coverage, more context is needed for safe and correct invocation.

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 description coverage is 0%, and the description provides no explanation of the parameters. The schema only shows types/format (e.g., transaction_id is a UUID, category is a non-empty string) but does not clarify what 'category' should contain—whether it's a category ID, a name, or must come from list_categories. The agent has no guidance on valid values, making correct invocation difficult.

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: 'Replace the category of one existing ZenMoney transaction.' It uses a specific verb ('replace') and resource ('category of one existing transaction'), distinguishing it clearly from siblings like delete_transaction or add_expense. The phrase 'one existing transaction' also clarifies it modifies an existing record rather than creating one.

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: this tool is for changing the category of a transaction. However, it provides no explicit when-to-use vs alternatives, such as 'if you need to update other transaction fields, use update_transaction_details instead.' The sibling update_transaction_details likely overlaps, so some exclusion guidance would be beneficial.

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