add_expense

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

No annotations are provided, so the description must carry the full behavioral burden. It only restates the create action without disclosing side effects, prerequisites (e.g., valid category), validation behavior, idempotency, or return value. The description adds no behavioral context beyond the tool name itself.

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 concise sentence with no filler words. It is front-loaded and easy to parse. It loses one point because it essentially repeats the tool name and provides no extra structural value.

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 input schema is rich and covers parameter semantics, and an output schema exists. However, the description lacks any behavioral or usage context beyond the basic create action. For a mutation tool with no annotations, this minimal description leaves the agent to infer when and how to use it safely.

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 100%, so the schema already documents all five parameters, including date format, amount exclusivity, category source, and optional note/subcategory. The description provides no additional parameter meaning, which aligns with the baseline score of 3 for complete 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 states a specific verb ('Add') and a clear resource ('a new expense entry to the database'). This immediately distinguishes the tool from its siblings (get_expense, list_expenses, update_expense, delete_expense, etc.) which use different actions on the same resource.

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?

There is no guidance on when to use this tool versus alternatives. The description does not mention that updates should use update_expense, deletions should use delete_expense, or that category validation can be done via list_categories. The usage context is left entirely to the agent's inference.

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