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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds rich behavioral context: data sources (SEC EDGAR/XBRL, FAERS, FDA, clinical trials), handling of off-calendar fiscal years, sorting by primary metric, and return of citation URIs. 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 efficient and front-loaded with key trigger phrases. Bold and structure are well used. Slight redundancy ('side-by-side comparison', 'parallel call') but overall it is appropriately sized and focused.

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's complexity, no output schema, and rich annotations, the description provides complete context: data sources, sorting, citation URIs, and even notes on fiscal year handling. An agent can fully understand what to expect and how to interpret results.

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%, but the description adds value by explaining the meaning of each enum (company: financials, drug: adverse events) and giving format examples for values (tickers/CIKs for company, names for drug). This goes beyond the schema's minimal 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?

Description explicitly states the tool does side-by-side comparison of 2-5 companies or drugs, with trigger phrases like 'compare X and Y', 'X vs Y', etc. It clearly distinguishes from siblings like entity_profile (single entity lookups) and positions itself as a replacement for 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 explicitly advises 'ALWAYS PREFER over sequential single-pack lookups when comparing entities', giving clear usage context. It also breaks down what data is pulled for each type. Lacks explicit 'when not to use' scenarios (e.g., detailed single-entity profiling), but the context is strong.

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