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

With no annotations, the description carries the full behavioral burden and does so well: it discloses the date range, YTD reset behavior for income/expense fields, quarter-end balance semantics, ratio formatting, merger_event behavior, and the FTE caveat. These are exactly the kind of behavioral traits an agent needs beyond the schema.

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?

The description is dense but justified by nine undocumented parameters and several behavioral caveats. It is front-loaded with purpose and usage, though the single long paragraph could be easier to scan if structured into shorter sections.

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?

For a complex nine-parameter query tool with no schema descriptions, the description covers most required context, including fields, aggregation options, grouping, and data quirks. It still leaves minor gaps around date parameter formatting and explicit routing versus some siblings, but the output schema handles return values.

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 description coverage is 0%, so the description must compensate, and it largely does: it defines cert, state format, size_band ranges, aggregate values and defaults, group_by behavior, and the full field list with definitions. However, start/end date format and min_assets units are not fully specified.

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 states a specific resource and scope: time series of one ratio or reported field for FDIC-insured banks over a defined date range. It also distinguishes the tool from its credit-union sibling by naming metric_series explicitly.

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?

It clearly explains the two main modes: provide cert for one bank, otherwise aggregate matching banks with optional state, size_band, and min_assets filters. It also gives an alternative for credit unions, but does not explicitly contrast usage with bank_peer_compare or query_metrics.

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