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

Reads like a data contract: states units (`asset`/`dep` in thousands), that the store is ACTIVE-ONLY so merged/failed banks are absent by construction, that the store can be REFUSED with DATA_UNAVAILABLE, the `limit` cap behavior, and the critical caveat that `ticker` is an Oxford Ledge mapping not FDIC-published. These go well beyond the readOnlyHint annotation.

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?

Front-loaded with the core purpose, then labeled blocks (UNITS, ATTRIBUTION) make dense content scannable. It is long but nearly every sentence carries operational information; the only minor cost is density.

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?

Despite having no output schema, the description names the return shape ({summary, query?, found?, institutions}), explains units, the active-only constraint, the refusal mode, and attribution limits. An agent has everything needed to call and interpret it.

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 100%, so the baseline is 3, but the description adds real meaning: `query` is a prefix (not substring) match restricted to active institutions with largest-asset-first ordering, and `limit` defaults to 25 with a hard cap of 100. This supplements the schema rather than repeating it.

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 (FDIC-insured banks and thrifts) and a precise operation: prefix search on `query` against ACTIVE institutions, or the largest active institutions when omitted. The distinction from sibling tools like ol_bank_structure_events is implied via the structure_event explanation, so an agent can select it correctly.

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?

Explicitly tells the agent when to pass `query` (name prefix) versus omit it (top-by-assets list) and explains the ordering. It also describes the failure mode (DATA_UNAVAILABLE) and the name-miss resolution path (structure_event), but does not name a sibling tool as a direct alternative.

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