Sync Bank (SimpleFIN)

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

Discloses side effect (refreshing balances), deduplication by provider id, and default non-re-pull behavior. Annotations do not provide such details, so description adds valuable transparency. No contradiction.

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 plus args/return notes, no fluff. Front-loaded with purpose, then default behavior, dedup, prerequisite, and structured args/return summary.

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?

Covers purpose, default vs override, deduplication, prerequisite, and return fields (accounts, newTransactions, store_span) despite no output schema. Missing: behavior when no prior transactions exist, but overall sufficient for a simple tool.

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 covers 100% of parameters with description. The tool description adds context: default behavior (since last stored transaction) and an example (365 for full refresh), which goes beyond the schema's 'Override' description.

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?

Clearly states the tool pulls new transactions and refreshes balances from SimpleFIN. Distinguishes from sibling tools like finance_import_csv (CSV import) and finance_balances (just balances) by specifying the source and action.

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?

Explains default incremental behavior (from day after latest transaction) and when to use days_back for full refresh. Mentions prerequisite finance_link_bank. Does not explicitly state when not to use, but the context is clear.

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