add_expense

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool creates a new entry (implying mutation) but doesn't reveal whether entries are editable/deletable afterward, how duplicates are handled, whether any validations apply to fields like amount or date, or what the response confirms. For a write operation with zero annotation coverage, this is a meaningful gap.

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 single-sentence description is efficient with zero wasted words. It's appropriately short for the overall tool. However, the brevity crosses over into under-specification given the 5 parameters and 0% coverage, so while concise it doesn't fully earn its brevity.

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 tool with 5 parameters, 0% schema coverage, no annotations, and no output schema, the description is severely incomplete. It provides no field format guidance, no return behavior, no error conditions, and no validation rules. A more robust description is warranted for a mutation tool of this complexity.

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%, meaning the description must compensate for the 5 undocumented parameters. The description names 'expense entry' but doesn't explain the format of date, amount, category, or the semantics of note and subcategory beyond their schema titles. Parameters like date (expected format?) and amount (currency? negative allowed?) are entirely unexplained.

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 'Add a new expense entry to the database' has a clear verb ('Add') and resource ('expense entry'), establishing the tool's core purpose. However, it doesn't differentiate from sibling tools like list_expenses or summarize effectively beyond the obvious add-vs-query distinction, and it lacks any detail about what an 'expense entry' comprises.

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 on when to use this tool versus alternatives. While the add-vs-list/summarize distinction is somewhat implicit in the name, the description doesn't state prerequisites, what category values are valid, or whether existing entries should be checked first. There are no explicit when-to-use or when-not-to-use instructions.

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