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

Annotations already indicate read-only, idempotent behavior. Description adds rich detail: for companies it pulls latest 10-K revenue/net income/cash/debt with correct fiscal year handling, for drugs it pulls FAERS/FDA/trial counts, results sorted by primary metric, returns paired data and 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?

Single paragraph, dense with information, front-loaded with examples and purpose. Every sentence adds value, but structure could be improved (e.g., separate sections for each type). Still efficient.

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 2 parameters, no output schema, and thorough annotations, the description covers input, data sources, sorting, return format, and efficiency. Missing details like data freshness or geographic scope (US-only for companies), but sufficient for an AI agent.

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 covers 100% of parameters with basic descriptions. The description adds substantial meaning: explains what each 'type' value retrieves (company vs drug data sources), and specifies format for 'values' (tickers/CIKs for company, names for drug) with range constraints. Greatly enhances 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 performs side-by-side comparison of 2-5 entities (companies or drugs) with trigger phrases like 'compare X and Y' and 'head to head'. It distinguishes from sibling tools like entity_profile by emphasizing parallel comparison 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 advises 'ALWAYS PREFER over sequential single-pack lookups when comparing entities' and claims it replaces 8-15 sequential lookups. Provides clear context for when to use, though could more explicitly mention alternatives like entity_profile for single entity lookups.

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