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

Annotations already indicate read-only, open-world, idempotent, non-destructive. The description adds data source details (SEC EDGAR/XBRL for companies, FAERS for drugs), correct handling of fiscal years, and sorting by primary metric. 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?

Dense but well-organized. Uses examples, explains data sources, and constraints (2-5 items, fiscal year handling). Every sentence adds value without wordiness.

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?

Despite no output schema, the description mentions return format (paired data + citation URIs). Covers entity types, data sources, sorting, and efficiency gain (replaces 8-15 sequential lookups). Complete for this tool's complexity.

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%. The description adds meaning beyond schema: explains data sources for each type, provides examples for values, clarifies sorting behavior, and mentions citation URIs in output.

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 concrete examples like 'Compare X and Y' and clearly states it performs side-by-side comparison of 2-5 companies or drugs in one call. It distinguishes from siblings like entity_profile by emphasizing parallel vs 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?

Explicitly states 'ALWAYS PREFER over sequential single-pack lookups when comparing entities.' It also specifies when to use company vs drug types and limited to 2-5 entities, providing clear guidance.

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