add_transaction

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

No annotations are provided, so the description carries the disclosure burden. It discloses the return value (transaction plus running total), amount sign convention, and the category existence requirement, which is meaningful behavioral context. It does not cover failure modes or side effects beyond insertion.

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 compact: a one-sentence purpose followed by three terse parameter bullets. Every sentence adds information and it is easily scannable.

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?

Although the core purpose is clear, the tool is incomplete for a 5-parameter no-annotation, no-output-schema case: 'source' is required but undefined, and there's no guidance on when to use add_transaction versus categorize_transaction. Error or rejection behavior for invalid categories is also unexplored.

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 description explains date, amount, and category, adding useful meaning beyond the bare schema. However, it omits the required 'source' parameter entirely and also does not explain 'note,' leaving 2 of 5 parameters undocumented despite 0% schema coverage.

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 opens with 'Insert a transaction and return it plus the category's running total for its month,' clearly identifying a create operation with a specific return value. The verb 'Insert' and resource 'transaction' distinguish it from read-only siblings like get_spending_summary and from categorize_transaction.

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 creating new transactions but provides no explicit when-to-use guidance or exclusions of alternatives like categorize_transaction. It does state a prerequisite (category must already exist), but does not say when to choose this tool over a sibling.

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