update_expense

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

No annotations are provided, so the description must disclose behavior on its own. It only states that an update occurs; it does not say whether unspecified fields are preserved or reset, how invalid IDs are handled, or whether permissions are required. This is a significant gap for a mutation tool.

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 is terse, but this is under-specification rather than effective conciseness. There is ample room to add key usage details without becoming verbose.

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 six parameters, an output schema, and no annotations, this description is far from complete. It does not specify what fields can be modified, whether partial updates are supported, or what the response contains; the presence of an output schema does not compensate for missing input and behavior context.

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% and the description names none of the six parameters. The agent must rely entirely on the raw schema, with no clarification of the required expense_id, optional fields, or default-to-null behavior. The description adds no value 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 names the action 'update' and the resource 'existing expense', and the qualifier 'existing' distinguishes it from add_expense. However, it is essentially a restatement of the tool name and provides no details on scope or which fields are affected.

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 about when to use this tool versus siblings such as add_expense or delete_expense. The only implied context is that the expense must already exist; there are no exclusions or alternative routing.

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