Update Expense

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

Given that annotations already indicate idempotentHint=true and non-destructive, the description adds value by specifying PATCH semantics and partial update behavior ('Only the provided fields will be changed'). No contradiction with annotations.

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 concise with two sentences and an example, but includes redundant bilingual text. It is front-loaded with clear purpose.

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 7 parameters (1 required) and an output schema, the description covers essential behavior (partial update) and usage. It does not detail error handling or validation, but given the output schema exists, it is sufficiently complete.

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 coverage is 100%, so the schema already describes all parameters. The description adds an example of usage (id, amount, category) and clarifies that only provided fields are changed, adding meaning beyond the schema.

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 'Update an existing expense using PATCH semantics' and provides an example with id, amount, and category. It distinguishes from sibling tools like list_expenses, delete_expense, etc.

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 updating an expense but does not explicitly state when to use this tool vs alternatives (e.g., other update tools). No when-not-to-use guidance is provided.

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