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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds significant behavioral context: data sources (SEC EDGAR/XBRL, FAERS, FDA), handling of off-calendar fiscal years, sorted results by primary metric, and paired data with citation URIs. 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 front-loaded with trigger phrases and a clear purpose. Each sentence adds value: parallel call efficiency, type-specific data, sorting behavior, and citations. Though moderately long, it is dense and free of 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 discloses return format (paired data + citation URIs), sorting behavior, and the specific data fields retrieved. It covers edge cases like off-calendar fiscal years. The only minor ambiguity is "primary metric," but overall it is complete for an agent to invoke correctly.

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 type and values, but the tool description adds substantial meaning: what each type pulls (company financials; drug adverse events), acceptable inputs for each (tickers/CIKs vs drug names), and the 2–5 range is reiterated with examples. This goes well beyond the schema.

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 purpose: side-by-side comparison of 2–5 companies or drugs in one parallel call. It uses specific trigger phrases like "Compare X and Y" and "X vs Y" and distinguishes itself from siblings by emphasizing it replaces sequential 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?

The description provides explicit usage guidance: "ALWAYS PREFER over sequential single-pack lookups when comparing entities" and gives concrete example intents (which is bigger/better, rank these companies). It differentiates between company and drug types and says it replaces 8–15 sequential lookups, implicitly telling when not to use single-entity tools.

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