add_expense

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

With no annotations, the description must disclose behaviors like side effects, permissions, or constraints. The description only says 'Add a new expense entry' without mentioning whether the operation is immediately persistent, requires authentication, or affects any existing data.

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 a single sentence, which is concise, but it is so minimal that it sacrifices informativeness. It would benefit from being slightly longer to include key parameter details.

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 that the tool has a complex input schema (5 parameters) and an output schema exists (but is not shown), the description should explain what the tool returns or confirms. It fails to provide enough context for an agent to confidently use the tool.

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 input schema has 0% description coverage, and the description adds no information about parameters. It does not explain the meaning of 'date', 'amount', 'category', or 'subcategory', leaving the agent to infer from names alone.

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 ('Add') and the resource ('a new expense entry'), which distinguishes it from sibling tools like list_expenses or summarize. However, it does not specify what fields constitute an expense entry beyond what's in the schema, which is a minor gap.

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 provided on when to use this tool versus alternatives like set_balance or summarize. There is no mention of prerequisites or scenarios where this tool is inappropriate, leaving the agent without decision support.

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