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

Annotations already declare readOnly/idempotent/non-destructive/openWorld=false, and the description adds operational context the annotations cannot: public SEC API, no API key required, and a coverage boundary ('IAPD covers RIAs registered with the SEC'). It stops short of noting pagination/result caps or latency for a search endpoint, which is the remaining behavioral gap.

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 scannable bullets and a workflow paragraph — good structure. The 'Geographic workflow' paragraph partially restates the bullets and the final Source/API-key line could fold into the note, so it is slightly longer than it needs to be.

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 an output schema and full annotations present, the description covers what an agent needs to select the tool: purpose, scope, alternatives, and auth-free access. Minor omissions (result limits, whether state-registered advisers are included) are not fatal but leave some ambiguity for a firm-search tool.

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?

The description confirms name-based lookup, but the schema exposes much more than a name — wholesaler_ids, source_resource_id (cache reuse), exclude_fillers, optional_additional_filters — and none of that semantics is echoed or prioritized in the description. Those auxiliary filters do carry their own $defs descriptions, so the description is not required to compensate fully, but it adds no meaning beyond the primary parameter.

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 (Search) and resource (SEC IAPD database for RIA firms), and enumerates what comes back (CRD, registration status, AUM, employee count, state, office city). It explicitly separates itself from the BD lookup path (BrokerCheck) and points to GetIAPDFirmDetail for depth, so an agent can place it among siblings without opening the 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?

Three explicit 'Use this tool when' bullets plus a named exclusion: 'For broker-dealers, use SearchBrokerCheckFirm instead.' It also spells out a handoff workflow (SearchBrokersByPlace → SearchIAPDFirm → GetIAPDFirmDetail), leaving essentially nothing to inference.

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