create_expense

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

Annotations already set destructiveHint=true, indicating a write operation. The description adds a visible warning emoji and user confirmation requirement, plus explicit structure for expense_lines and payments. This goes beyond the annotation without contradicting it. However, it does not fully describe all behavioral traits (e.g., idempotency, side effects).

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 relatively short and uses line breaks to separate concerns. It front-loads the purpose and warning. However, the inline parameter structures could be cleaner (e.g., proper formatting), and the information is somewhat crammed into a single block.

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 the tool's complexity (10 parameters, nested objects), the description partially explains the most complex fields (expense_lines, payments) but omits required fields like date, draft, provider, and optional ones like tags. With an output schema present, return values need not be covered, but overall completeness is adequate but not thorough.

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, so the description must compensate. It provides subfield details for expense_lines (description, base, tax, retention, imputation, expense_type, investment, investment_data) and payments (amount, payment_method, paid, origin_account, date, destination_account), plus document_type and vat_eu conditions. This adds significant meaning, though several parameters (date, draft, provider, document_number, annotations, tags) are not explained.

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 'Crea un gasto' (creates an expense), providing a specific verb and resource. It distinguishes from siblings like create_income by focusing on expenses. The warning emoji and 'Confirmar con usuario' do not detract from the clear purpose.

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 (e.g., create_income or update_expense). The only usage hint is 'Confirmar con usuario' (confirm with user), which is a safety note, not a when-to-use condition.

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