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

Beyond the readOnly/idempotent annotations, the description reveals important behaviors: parallel fan-out (ONE parallel call), fallback chain (GDELT→GNews), and a soft-fail for patents until May 2025. Also clarifies that names are not supported. These are critical operational details not otherwise available.

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 dense with necessary information. It is front-loaded with trigger examples and structured by return field groups. It avoids fluff, but the density makes it slightly harder to parse at a glance; a short bulleted list could improve scanability.

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?

Given there is no output schema, the description covers all essential context: input constraints, exact outputs, data sources, failure behavior, and alternatives. It even specifies URI templates for filings. This is comprehensive for a read-only aggregation tool.

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?

The schema already covers both parameters with 100% description coverage, so the bar is baseline 3. The description adds value with concrete examples ("AAPL", "0000320193") and reinforces the zero-padded CIK requirement, providing operational clarity beyond the schema text.

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 intents ("Tell me about X" / "research Acme") and clearly states it produces a 'full cross-source profile of a US public company in ONE parallel call.' It enumerates exact return fields (cik, company_name, recent_filings, fundamentals, patents, news, LEI), distinguishing it from sibling tools like resolve_entity (which handles name resolution) and 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?

Explicit guidance: 'ALWAYS PREFER over chaining single-pack SEC/XBRL/news lookups when the user asks for a holistic view' tells the agent when to use it. It also specifies an alternative: 'use resolve_entity first if you only have a name.' This gives clear positive and negative use conditions.

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