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

Beyond the readOnly/openWorld/idempotent annotations, the description discloses concrete runtime behavior: multi-source fan-out, soft-fail on the USPTO PatentsView API, the semantics of sources_used/sources_failed, empty sections meaning genuine 'no data', and the resolved:false behavior for private companies. This is rich operational detail not derivable from annotations.

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 dense and front-loaded with usage examples, then flows into return structure and edge cases. It is longer than strictly necessary and slightly redundant with the schema's enum explanation, but nearly every clause adds operational value, so it remains effectively structured for an agent.

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 full burden of explaining return shape, and it does so thoroughly: CIK/company_name/resolved_from/resolved_to, recent_filings, fundamentals, patents, federal_contracts, fda_products, hiring, news, and LEI fields. It also covers failure modes and input alternatives, making it complete 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?

Input schema already covers both parameters 100%, so the baseline is 3. The description adds meaning by noting that the type values are interchangeable, that value can be a ticker, zero-padded CIK, or company name, and that names resolve via SEC EDGAR's company-name match. This goes beyond the schema text with practical examples.

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 user queries and defines the tool as a 'full cross-source profile of a US public company in ONE parallel call.' It clearly states a specific verb (profile/research/brief) on a specific resource (company) and distinguishes itself from chaining single-pack lookups.

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?

It explicitly says 'ALWAYS PREFER over chaining single-pack SEC/XBRL/news lookups when the user asks for a holistic view,' giving a clear routing rule. It also enumerates all accepted input forms, so an agent knows exactly when to invoke this tool versus a more piecemeal lookup.

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