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

Annotations already declare the safety profile (readOnly, idempotent, openWorld, non-destructive), so the bar is low. The description still adds real context beyond structured fields by disclosing the data source (Form AP filings), which implies coverage is limited to reported engagements rather than all possible audits.

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 resource and scope, then input format, then example queries. Minor redundancy in re-stating that the firm argument accepts a name or numeric ID, already covered by the schema.

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, and the description sufficiently conveys what comes back (a set of issuers scoped to a firm and optional fiscal year). Pagination/default-limit behavior lives in the schema, so the description is complete enough for correct invocation.

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 100%, so the schema already documents firm, limit, and fiscal_year. The description only restates the firm identifier forms (name or numeric ID) without adding matching or formatting detail beyond what the schema's own parameter description provides — baseline 3.

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 combination: returns every issuer that a PCAOB-registered firm reported auditing, with the firm as the query anchor. The direction of the lookup (firm → issuers) is unambiguous, but it never names or distinguishes itself from the reverse-direction sibling pcaob_auditor_of or the partner-level pcaob_partner_engagements.

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 concrete user-shaped questions that map to this tool ("every issuer audited by Deloitte in 2025", "how many public companies does BDO audit") and notes the optional fiscal-year scoping, which is clear invocation context. It stops short of exclusions or explicit routing away from sibling PCAOB tools.

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