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

Beyond the readOnly/openWorld annotations, it discloses required auth scopes, the per-call cost and API key requirement, the return shape (entries + per-currency totals), and the important behavior that records carry inspect_url and must not be linked from an id, with inspect_note indicating missing pages. It also clarifies the ledger reuses existing expenses rather than a parallel table. This is rich disclosure the annotations cannot convey.

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?

Front-loaded with the core purpose and source columns, then auth, then return shape and the inspect_url rule. Dense and telegraphic but nearly every clause carries information. The inspect_url/citation guidance is slightly verbose relative to its importance but still earns its place.

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?

An output schema exists, so return values need not be fully explained, and the description still summarizes them plus per-currency totals. With auth requirements, cost, key requirement, and the inspect_url/link rule all covered, an agent has everything needed to call and correctly report results.

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 schema already documents to/from, limit, name, and person_id. The description's 'Pass person_id or name' hints at a one-of relationship between two params, adding marginal meaning, but does not explain the inclusive date semantics or limit bounds beyond the schema. Baseline 3 applies.

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 resource and scope: a money ledger between the user and a contact, sourced from individual expenses via paid_to_person_id / income_from_person_id. That sourcing detail implicitly separates it from general tools like get_transactions or get_expenses. It never names its closest sibling get_money_between_people, so the differentiation is left to inference.

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?

It gives a concrete usage rule ('Pass person_id or name') and states the required scopes (context.read, financial_details:read), which is real guidance. However it never says when to choose this over get_money_between_people or get_transactions, nor when not to use it. Usage is implied rather than framed against alternatives.

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