Person Transactions

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds valuable non-obvious context beyond annotations: it reuses existing expense records rather than maintaining a parallel ledger, and it notes cost and API key requirements. 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?

Two sentences deliver the core purpose, inputs, outputs, data source, cost, and authentication requirement with no filler. The information is front-loaded and every clause carries meaning.

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 a full input schema, complete parameter descriptions, read-only annotations, and an output schema available, the description covers the remaining important context: data derivation, required identifier style, return shape, and operational considerations. Nothing critical for invoking the tool correctly 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 coverage is 100%, so the baseline is 3. The description adds meaningful semantic guidance by connecting person_id/name to the ledger concept and explaining the data source ('paid_to_person_id / income_from_person_id'), which helps an agent understand how parameters relate to the domain.

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 defines the tool as a 'Me↔contact money ledger' built from expense fields, which is a specific verb+resource. It also states what it returns ('entries + per-currency totals') and distinguishes it from a generic expense query by focusing on person-related transactions.

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 clear usage context: pass person_id or name to get person-to-person money movement. It does not explicitly name alternatives like get_transactions, search_transactions, or get_money_between_people, nor does it state when not to use this tool, but the 'person ledger' framing strongly implies the intended use case.

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