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

Annotations only declare readOnlyHint=true, and the description adds substantial behavior beyond that: newest-first ordering, is_failure from the CHANGECODE taxonomy, name resolution across active AND closed charters, the resolved_from field, ambiguous-candidate return behavior, and the DATA_UNAVAILABLE error contract. This is rich disclosure for a read tool.

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?

Effectively one dense paragraph, front-loaded with what the tool returns before the parameter and error guidance. Every clause carries information, though the run-on length is slightly heavier than ideal.

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 and only a readOnlyHint annotation, the description still conveys result ordering, key flags (is_failure, resolved_from), ambiguity handling, and error semantics. An agent has everything needed to call it correctly and interpret failure modes.

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 meaningfully extends the schema: it explains the cert-vs-name tradeoff, that name resolution spans closed charters, and the resolved_from/ambiguous outputs that follow from parameter choice. It adds semantics rather than restating types.

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 structural events for one bank) plus the event types covered and ordering, and explicitly distinguishes itself from sibling ol_fdic_bank ('active institutions only'). An agent can tell it apart from the sibling without opening any 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?

Explicit about which parameter to pass (cert or name), what happens when name is ambiguous ('call again with the cert'), and which sibling to prefer for active-institution questions. Nothing about when-to-use is left to inference.

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