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

Annotations already declare readOnlyHint=true and openWorldHint=false. The description adds real behavioral context beyond that: a 25-credit cost against the API key, a free path via a state watch, and the fact that results are organizations only (not branches or people). It stops short of describing result limits or whether all branches are counted.

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 short sentences, front-loaded with the payload, then cost, then the org-only constraint. No filler and nothing buried.

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?

With no output schema, the description still states what comes back (branch counts and assets) and discloses the credit cost, which is the main decision input. Minor gaps remain around result caps and whether the kind filter defaults to both, but nothing essential to a correct call is missing.

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 50%: county is documented as 5-digit FIPS, kind is not but its enum (bank/credit_union) is self-describing. The description's 'one county' and 'bank and credit union' reinforce scope and the default both-kinds behavior. Baseline 3 is appropriate since the schema does most of the work.

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 names a concrete resource set and payload: 'Every bank and credit union with a branch in one county, with branch counts and assets.' An agent immediately knows what it retrieves. It doesn't explicitly differentiate itself from siblings like get_bank_access or order_bank_report, which keeps it below a 5.

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?

'Organizations only' and '25 credits from the API key (free with a watch for that state)' imply when this is worth calling and hint at the free alternative path, but no sibling tool is named and there are no explicit when-not-to-use conditions. Usage is inferable rather than stated.

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