Money Between People

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

Annotations already cover read-only and non-destructive behavior. The description adds valuable operational traits beyond annotations: cost ($0.10), API key requirement, and the precise scoping 'authenticated user ↔ one contact via expenses FKs.' No contradictions 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 compact and front-loaded: it establishes the relationship to get_person_transactions first, then adds the alias rationale and cost constraints. Every sentence earns its place with no filler or redundancy.

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?

With 100% schema parameter coverage, an output schema, safety annotations, and an explicit pointer to the sibling tool, the description is nearly complete. It could directly restate the return behavior instead of relying on 'Same as get_person_transactions,' but the alias framing makes this a minor gap.

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 100%, so the baseline is 3 even without extra parameter details in the description. The description's scoping phrase 'one contact via expenses FKs' gives some context for person_id/name, but it does not add meaningful syntax or format details 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 states the tool's function via 'Same as get_person_transactions: authenticated user ↔ one contact via expenses FKs,' which clearly specifies a verb, resource, and scope. It also distinguishes itself from the sibling by explicitly naming get_person_transactions and framing this as an alias, so an agent can tell them apart.

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 gives explicit selection guidance: 'Prefer get_person_transactions; this alias exists for agent discoverability.' This tells the agent when not to use this tool and points to the preferred alternative, leaving no ambiguity about routing.

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