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

Annotations already carry readOnlyHint/openWorldHint/idempotentHint, but the description adds substantial behavioral context: fan-out across seven source families, fallback chains, sources_used/sources_failed semantics where an empty section means real "no data," name-resolution via SEC EDGAR, and resolved:false+notes behavior for private companies. No contradiction with 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 information-rich, and the query-example opening is effective front-loading. However, the middle return-field enumeration is a run-on wall of text with garbled/corrupted segments (patents/contracts/fda_products sections), which hurts parseability. Every sentence earns its place, but the structure does not.

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?

For a complex multi-source tool with no output schema, the description carries the full return-value burden and succeeds: it covers cik/company_name, recent_filings with URIs, fundamentals fields, sources_used/sources_failed, input forms, and edge cases. Nothing an agent needs to invoke this 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 baseline is 3; the description pushes higher by adding concrete value examples ("AAPL", "0000320193", "Moderna"), the zero-padding requirement, the resolved_from/resolved_to behavior when a name is passed, and the private-company resolution edge case. It goes beyond the schema's already-good parameter docs.

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 states a specific verb-resource-scope: "full cross-source profile of a US public company in ONE parallel call," anchored by concrete query examples ("brief me on Tesla", "company profile for Microsoft"). It explicitly distinguishes itself from chained single-pack SEC/XBRL/news lookups, so an agent can tell it apart from sibling research tools.

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 gives a strong preference rule: "ALWAYS PREFER over chaining single-pack SEC/XBRL/news lookups when the user asks for a holistic view." It also clarifies input-format flexibility and the private-company fallback path. It does not explicitly name sibling alternatives like resolve_entity (lightweight resolution) or compare_entities, so the exclusion logic is implicit rather than fully enumerated.

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