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

Annotations already declare read-only, idempotent, non-destructive behavior, but the description adds substantial context: it fans out across five sources, notes the patent API sunset with a soft-fail, mentions the GDELT→GNews fallback chain, and details the return structure (e.g., 'fundamentals (LATEST 10-K... sorted period_end DESC)'). This goes beyond the annotations and sets accurate expectations about limitations.

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 information-dense: every sentence earns its place. It opens with concrete user prompts, immediately states the core purpose, then packs in sources, return fields, and input constraints using a compact semicolon-separated structure. There is no fluff or redundancy.

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 fully covers the return contract: CIK and company name, up to 5 filings with URIs, specific fundamentals metrics and sorting, patent status and soft-fail, news fallback chain, and LEI. It also covers input formats and the resolve_entity alternative. This is highly complete for a complex cross-source 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?

Schema description coverage is 100%: the schema already explains the 'type' enum and 'value' as ticker/CIK with the 'names not supported' caveat. The tool description repeats this information nearly verbatim, without adding new meaning beyond the schema. The baseline of 3 applies because the description does not enrich parameter semantics beyond what the schema provides.

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 clearly states the tool's function with a specific verb+resource: 'full cross-source profile of a US public company in ONE parallel call.' It is distinguished from siblings through the explicit 'ALWAYS PREFER over chaining single-pack SEC/XBRL/news lookups' guidance and by listing the exact data sources and return fields, leaving no ambiguity about what the tool 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?

The description includes explicit usage timing ('when the user asks for a holistic view'), a strong preference directive ('ALWAYS PREFER'), and clear when-not-to-use guidance: names are not supported, so 'use resolve_entity first if you only have a name.' This provides clear alternatives and exclusions.

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