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

The description goes far beyond the readOnly/idempotent/openWorld annotations by explaining multi-source fan-out, resolved_from/resolved_to behavior, empty sections meaning 'real no data', private-company fallback with notes, and expected absence of FDA data for small-molecule drugs. This gives the agent accurate expectations for unusual outcomes.

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 long but unusually information-dense; nearly every clause supplies operational detail (source names, return fields, fallback behavior). It is front-loaded with triggers, though the single-paragraph structure and repeated mentions of source lists make it less scannable than it could 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 no output schema, the description carries the burden of explaining return values, and it does: cik, company_name, resolved fields, recent_filings with URIs, fundamentals, and sources_used/sources_failed. It also covers input flexibility, expected empty sections, and failure semantics for private companies, leaving no critical gap 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 coverage is 100%, so baseline is 3. The description adds value by explicitly enumerating accepted shapes ('AAPL', '0000320193', 'Moderna'), clarifying type interchangeability, and noting EDGAR name resolution and the private-company resolved:false case, which enriches the schema's terse descriptions.

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 opens with concrete trigger phrases and defines the tool as a 'full cross-source profile of a US public company' in one parallel call. It is immediately distinguishable from single-pack SEC/XBRL/news lookups and covers a clear resource scope.

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?

The description provides explicit trigger examples ('tell me about X', 'research Acme', 'brief me on Tesla') and states to 'ALWAYS PREFER' this over chaining single-pack lookups when a holistic view is requested. It does not explicitly name a sibling comparison tool or state exclusion cases, so it stops short of a full when/not guidance.

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