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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint true and destructiveHint false. The description adds extensive behavioral context: it fans out across multiple sources (SEC EDGAR, XBRL, USPTO, GDELT, GLEIF), explains soft-failure of patents due to sunset, and details return fields (cik, filings, fundamentals, etc.). No contradiction.

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 but front-loaded with examples and key guidance. Every sentence carries weight, though it could be slightly more structured (e.g., bullet points for returned data). However, given the complexity, the length is justified.

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?

No output schema exists, but the description compensates by detailing return fields and sources. Two required parameters are fully documented. For a tool of this complexity (multi-source, multiple sub-tools behind the scenes), the description is comprehensive.

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% with descriptions for both parameters. The description adds significant meaning by specifying valid inputs (ticker like 'AAPL' or zero-padded CIK), explicitly excluding names, and referencing a sibling tool (resolve_entity) for alternative identification.

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 uses specific verbs like 'tell me about', 'research', 'brief me on' and clearly states it returns a 'full cross-source profile of a US public company in ONE parallel call'. It distinguishes itself from chaining single-pack lookups, making the purpose very clear.

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?

Explicitly states 'ALWAYS PREFER over chaining single-pack SEC/XBRL/news lookups when the user asks for a holistic view' and 'names not supported (use resolve_entity first if you only have a name)'. Provides clear when-to-use and when-not-to-use guidance.

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