money_summary

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

Beyond the readOnlyHint annotation, the description adds meaningful behavioral context: it aggregates across all friends, reports totals per currency, breaks out owed vs owe, includes per-friend balances, and includes simplified group debts. It does not explain the simplification algorithm or auth prerequisites, but it discloses the core behavior sufficiently.

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 dense sentence that front-loads the core value proposition ('One-call financial overview') and then enumerates the exact outputs. Every phrase earns its place and there is no fluff or repetition.

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 no-parameter read-only tool, the description is largely complete: it states scope, output categories, and even the alternative it replaces. The lack of an output schema means exact field names are not disclosed, but that is not essential for selecting and invoking this tool correctly.

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?

The tool has zero parameters, so there is no parameter burden for the description to carry. The baseline for no-parameter tools is 4, and the description contains nothing misleading or unnecessary about inputs.

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 identifies a specific resource and purpose: a one-call financial overview with per-currency owed/owe totals, per-friend balances, and simplified group debts. It also distances itself from manual aggregation over get_friends/get_groups, making it easy for an agent to know what this tool uniquely provides.

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 explicitly says this replaces manual aggregation over get_friends/get_groups, giving a concrete when-to-use signal. It doesn't spell out when not to use it or name direct sibling alternatives, but the use case is clear enough for a no-parameter read-only tool.

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