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

Despite annotations already covering read-only/idempotent/destructive safety, the description adds rich behavior: it fans out across enumerated sources, returns sources_used/sources_failed, treats empty sections as real no-data, soft-fails on patents API sunset, and explains expected empty FDA results for small-molecule companies. This goes well beyond what annotations reveal and prevents false-negative interpretation.

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?

A dense but front-loaded description: trigger examples and the core directive come first, followed by source enumeration, return semantics, failure behavior, and parameter details. Each clause contributes operational knowledge or prevents a wrong call, and the length is justified by the tool's complexity.

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 values and edge cases, and it does so thoroughly: sections returned, URI format for filings, resolved_to/resolved_from, source success/failure reporting, and private-company fallback. No critical operational behavior is left unstated.

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 covers 100% of parameters, so baseline is 3. The description adds genuine value by explaining that type values are interchangeable, value accepts ticker/CIK/company name, CIK should be zero-padded, name resolution uses SEC EDGAR's match, and private companies return resolved:false with notes.

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 query triggers and defines a specific resource: a full cross-source profile of a US public company. It distinguishes the tool from single-pack SEC/XBRL/news lookups by declaring 'ALWAYS PREFER' for holistic requests, leaving no ambiguity about what entity_profile does.

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 provides explicit usage conditions: use when the user asks for a holistic view, and prefer over chaining single-pack SEC/XBRL/news lookups. It lacks an explicit when-not/alternative mapping to siblings such as compare_entities or resolve_entity, so selection guidance is strong but not exhaustive.

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