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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, destructiveHint. Description adds value: explains that company type pulls latest 10-K financials and handles off-calendar fiscal years, and drug type pulls FAERS and FDA data. 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?

Description is somewhat long but packs essential information. Front-loads purpose and usage hints. A few minor redundancies but overall efficient for the complexity.

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?

No output schema, but description explains return format: paired data, citation URIs, sorted by primary metric. Covers both entity types in detail. For a tool with simple parameters and no nested objects, it is very complete.

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% (both parameters described). Description adds examples ('AAPL','MSFT' for company; 'ozempic','mounjaro' for drug) and constraints (maxItems 5). Explains what data each type pulls, adding meaning 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 clearly states the tool provides side-by-side comparison of 2-5 companies or drugs. Uses specific verbs like 'compare' and refers to the resource (companies/drugs). Distinguishes from sibling tools like entity_profile by emphasizing parallel call 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 says 'ALWAYS PREFER over sequential single-pack lookups when comparing entities' and provides natural language examples like 'which is bigger / better / larger'. Clearly indicates when to use this tool over alternatives.

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