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

Annotations already declare readOnly/openWorld/idempotent; the description adds sourcing (SEC EDGAR/XBRL, FAERS/FDA), fiscal-year handling, sorting by primary metric, and per-entity citation URIs. No contradiction is present.

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 packs many facts into a compact block. Each sentence contributes a distinct piece: triggers, preference rule, type-specific behavior, sorting, and return format.

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?

For a two-parameter tool with no output schema, the description covers inputs, data sources, sorting, output shape (paired data + citation URIs), and efficiency gain over sequential lookups. No critical behavioral gap remains.

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 input schema has 100% coverage, but the description adds meaning: type='company' maps to financial metrics, type='drug' to FAERS/FDA/trial counts, and values are illustrated with ticker/CIK and drug-name examples. This goes beyond the schema's simple enum.

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 trigger phrases and states 'side-by-side comparison of 2–5 companies or drugs in ONE parallel call.' It explicitly differentiates from sequential single-pack lookups, making the purpose unmistakable.

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 'ALWAYS PREFER over sequential single-pack lookups' sentence provides an explicit alternative and when-to-use rule. It also enumerates trigger examples ('which is bigger', 'rank these companies') and clarifies domain types.

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