get_expense

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

Annotations already declare readOnlyHint true, idempotentHint true, and destructiveHint false, so the safety profile is established. The description adds valuable behavioral context about the response contents: it returns a single expense's full detail, including splits and the comment thread, which is not inferable from the schema alone.

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, front-loaded sentence with no filler. It efficiently conveys the action, the resource, and the key content of the response.

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 simple read-only tool with one parameter, existing annotations, and an output schema, the description is complete enough for an agent to invoke it correctly. It identifies exactly what will be returned and does not need to explain return values because an output schema exists.

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%, so the description should compensate by explaining the expense_id parameter, but it does not mention it at all. The parameter name and type are self-explanatory to some degree, but the description adds no meaning beyond the schema's field name and integer type.

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 ('Fetch'), a specific resource ('one expense'), and the scope of what is returned ('full detail, including its splits and comment thread'). This clearly distinguishes it from list_expenses, which retrieves multiple expenses, and from the mutation siblings.

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 makes the intended use clear: call this tool when you need the full detail for a single expense. It does not explicitly name alternatives or exclusion conditions, but the 'one expense' phrasing and the tool name provide sufficient context for when to use it.

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