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

Annotations only give readOnlyHint=true, so the description carries real weight and delivers: curated universe rather than live EDGAR full-text, prefix-match ranking, the meaning of an empty filers array (store answered, nothing matched) versus a REFUSED DATA_UNAVAILABLE error on an unreachable store, and that caveats ride in tool_notes.

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 purpose and routing before the caveats; dense with caps and parentheticals but nearly every clause carries information an agent needs. Slightly cramped punctuation keeps it from a 5.

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, yet the description specifies the return shape ({summary, query, filers:[{cik, name, last_filing, page_url}], count}), the empty-result semantics, the failure mode, and where caveats live — nothing needed to call or interpret it correctly is missing.

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 adds semantic value beyond the schema by disclosing that 'name-PREFIX matches rank first' and repeating the 3-80 char and default-5/hard-cap-10 bounds in context.

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 ('Resolve a 13F FILER name to its CIK') and explicitly distinguishes itself from search_company ('search_company resolves ISSUERS'), so an agent can pick it apart from the closest sibling without opening schemas.

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?

Explicitly frames itself as 'the front door to get_13f_holdings and ol_13f_filer_analytics when you know the manager and not its CIK', naming the downstream tools and the exact condition that selects it, plus the contrast with search_company.

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