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

Annotations only declare readOnlyHint=true, so the description carries the rest and does so well: unreachable FDIC store surfaces as DATA_UNAVAILABLE rather than an empty list, ambiguous names return a candidate list instead of guessing, and caveats are delivered via the response's tool_notes. Ambiguity and failure semantics are exactly the behavioral traits an agent needs before trusting an empty result.

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 resource and event taxonomy, then the resolution/error semantics. Dense and clause-heavy (em-dashes, backticks, parentheticals) but nearly every clause carries operational information; the only mild slack is the redundant 'FREE'/'Source' pairing at the end.

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?

No output schema exists, so the description must describe returns — and it does: is_failure from the CHANGECODE taxonomy, resolved_from, ambiguous candidate lists, tool_notes. Combined with the resolution and unavailable-store behavior, an agent has everything needed to call this correctly and interpret the response.

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 baseline would be 3, but the description adds real semantics beyond the schema: name resolution spans active AND closed charters, resolved_from reports which charter matched, and ambiguous resolution returns candidates. It doesn't cover `limit` behavior beyond the schema's own default/cap note, keeping it just short of a 5.

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 verb+resource: FDIC structural events for one bank, enumerating the event types (failures, assisted resolutions, mergers, acquisitions, charter changes) and the sort order. It explicitly distinguishes itself from the sibling ol_fdic_bank by noting that tool covers 'active institutions only', so an agent can route without opening either schema.

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 explicit invocation guidance: pass `cert` or `name`, call again with `cert` when a name is ambiguous, and use ol_fdic_bank instead for active-institution data. It also pre-empts the most likely user mistake (assuming a failed/merged bank can't be found).

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