get_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. 'Get' clearly indicates a non-mutating read operation, but the description does not mention behavior for missing IDs, permissions, or error cases. This is acceptable for a simple getter but leaves some ambiguity.

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?

A single, front-loaded sentence with no filler or redundancy. Every word contributes to understanding the tool's core behavior.

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 one-parameter getter with an output schema, the description is nearly complete. It covers what the tool does and how the parameter is used. It could mention not-found behavior, but the output schema likely handles return-value documentation, so nothing critical is missing.

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%, but the description does add meaning by identifying the parameter as the lookup key for a single expense. However, the parameter name 'expense_id' is already self-descriptive, and the description adds minimal detail 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 uses a specific verb ('Get'), a concrete resource ('expense'), and a precise selection mechanism ('by ID'). It clearly distinguishes this tool from broader tools like list_expenses or summarize_expenses.

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 phrase 'single expense by ID' clearly implies the tool is for retrieving one specific expense when its ID is known. It doesn't explicitly name alternatives or exclusion conditions, but the singular 'by ID' provides enough context to select it over list-style siblings.

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