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

The description reveals behavioral details beyond annotations: it specifies data sources (SEC EDGAR/XBRL for companies, FAERS for drugs), mentions sorting by primary metric, and notes off-calendar fiscal year handling. Annotations already mark it as read-only and idempotent, and the description adds no contradictions.

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 concise yet comprehensive, front-loading trigger phrases and then providing structured details. Every sentence adds value: use guidance, type-specific behavior, sorting, and efficiency claim. No filler or repetition.

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?

Given the tool has only 2 parameters (type, values) and no output schema, the description fully covers input constraints, behavior for each type, result ordering, and citation output. An agent can invoke this tool correctly without additional context.

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, but the description adds rich context: examples for values (tickers/CIKs for company, drug names), explains what each type returns (revenue/net income/cash/debt vs. adverse-event/FDA/trial counts), and specifies min/max limits. This goes well beyond the schema's type descriptions.

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 defines the tool's purpose: side-by-side comparison of 2-5 companies or drugs. It uses specific action verbs like 'compare', 'rank', and 'head-to-head', and distinguishes it from siblings like 'entity_profile' by explicitly stating it replaces multiple sequential 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 guidance on when to use this tool: 'ALWAYS PREFER over sequential single-pack lookups when comparing entities.' It includes example query triggers and specifies the number of entities (2-5) and types (company/drug), leaving no ambiguity about appropriate use.

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