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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds value by detailing data sources (SEC EDGAR/XBRL for companies, FAERS for drugs), sorting by primary metric, and citation URIs. No contradictions 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 a single, dense paragraph that front-loads usage triggers and purpose. Every sentence adds value, though it could benefit from slight structural separation for readability.

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 no output schema, the description partially covers return format ('paired data + citation URIs') and sorting. It lacks a precise description of the output structure (e.g., side-by-side comparison fields for financials vs adverse events). For a tool with moderate complexity, this is adequate but not 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%. The description enriches both parameters: explains the type enum with specific data pulled for each value, and clarifies the values array with examples (tickers/CIKs for company, drug names for drug). Adds meaningful context beyond 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 provides a specific verb ('compare'), resource ('companies or drugs'), and constraints ('2–5 entities in ONE parallel call') with natural language triggers. It clearly distinguishes from siblings like entity_profile by explicitly stating preference over 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 explicitly states when to use this tool ('ALWAYS PREFER over sequential single-pack lookups when comparing entities') and implies when not to (single entity). However, it does not name alternative tools like entity_profile for singular lookups.

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