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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld). The description adds real behavioral context beyond that: a two-stage resolution (ticker/name → SEC CIK, then fallback to the internal Form AP index) and an enumeration of returned fields.

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?

Three sentences, front-loaded with the core question the tool answers, followed by mechanics and return fields. Efficient, though the quoted example phrasings are slightly more verbose than strictly necessary.

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, the description compensates by enumerating the return fields (firm name/id, engagement partner, report date, fiscal period end). Combined with the resolution behavior and use cases, an agent has everything needed to invoke it correctly.

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% and the single parameter is documented in the schema itself. The description adds meaning over the schema by explaining how the value is resolved (ticker or name → CIK, with a name-search fallback), which helps an agent understand accepted input forms.

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: identifies the PCAOB-registered audit firm and engagement partner for a company. It is clearly distinguishable from siblings like pcaob_firm_engagements and pcaob_partner_engagements because it is company-centric rather than firm- or partner-centric.

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?

Provides concrete use cases ("who audits Apple", "Tesla's audit engagement partner") and explains when the fallback path applies (funds, broker-dealers without a clean SEC ticker). It does not explicitly name the sibling tools to prefer for firm- or partner-first queries, so routing isn't fully closed.

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