list_balance_modifiers

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

The description adds significant behavioral context beyond the readOnlyHint annotation. It discloses that subjectReference is enforced client-side within the fetched page, impacting efficiency expectations. It also explains the verbose parameter's default behavior and context savings (90%). 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?

Three sentences, each serving a distinct purpose: purpose, usage example, and behavioral note. No filler or redundant information. Front-loaded with the core message.

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?

The tool has no output schema, but the description compensates by detailing the verbose parameter's behavior. It covers pagination implicitly and addresses filtering behavior. For a list endpoint, this provides sufficient context for an agent to select and invoke 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?

Schema description coverage is 100%, so baseline is 3. However, the description enriches the semantics: it provides concrete examples for subjectReference ('invoice:<id>' or 'bill:<id>'), clarifies client-side enforcement, and explains the verbose parameter trade-off (context savings). This goes well beyond the schema descriptions.

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 states the tool lists 'balance modifiers (payment associations)' and provides a specific usage example filtering by 'subjectReference'. The verb 'List' and resource 'balance modifiers' are distinct from sibling tools like list_accounts, list_bills, etc. The purpose is unambiguous and differentiated.

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 a clear when-to-use example: 'Filter by subjectReference ... to see which payments settled a specific invoice or bill'. This explicitly ties the tool to a common use case. It does not explicitly list alternatives or when-not-to-use, but the context is sufficient for most cases. Sibling tools like list_bank_payments serve different purposes, so confusion is unlikely.

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