Bank balances

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description's job is to add semantics — and it does, disclosing the snapshot/staleness model and the reporting obligation around as_of. That is exactly the kind of non-obvious behavior an agent would otherwise get wrong. It does not mention freshness lag beyond the monthly cadence or any account-visibility limits.

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, both load-bearing, with the resource definition front-loaded and the staleness caveat immediately after. No restatement of the name or title and no filler.

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 no explanation, and the description covers the one thing that would cause misuse: treating snapshots as live balances. What is missing is positioning relative to the many sibling financial tools, which would help an agent choose correctly. Otherwise complete for a one-parameter read 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?

There is a single optional parameter and the schema documents it fully, including the default and the 120-snapshot cap. The description adds no additional meaning about what history does or when to request it, so the schema carries the load. Baseline 3 is appropriate given 100% schema description coverage.

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?

States a specific resource and its shape: the company's own bank accounts, broken out per account and summed per currency. That is far more informative than the title alone and distinguishes it from sibling overview tools by naming the granularity. It stops short of explicitly naming the sibling it replaces (e.g. get_financial_overview or get_business_snapshot).

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?

Gives a concrete usage constraint that changes how the agent interprets results: the data is monthly opening-balance snapshots dated the 1st, not live balances, and the as_of date must always be quoted. It does not say when to prefer this over the other financial sibling tools, so no explicit exclusions are offered.

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