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

Annotations already mark it read-only, open-world, idempotent, non-destructive. The description adds significant behavioral detail: sources (SEC EDGAR/XBRL for companies, FAERS for drugs), handling of off-calendar fiscal years, result sorting, and citation URI provision. 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 front-loaded with example queries, then explains behavior per type, and ends with a benefit. Every sentence is informative; no filler. It is appropriately sized 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?

With only 2 parameters and full schema coverage, the description fully explains what to expect: paired data, citation URIs, sorted results. No output schema needed given the detailed behavior description.

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%, so baseline is 3. The description goes beyond by explaining that for 'company' type it uses tickers/CIKs and pulls revenue/net income/cash/debt, and for 'drug' type it pulls FAERS counts. This adds meaningful context beyond schema 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?

The description clearly states it performs side-by-side comparison of 2–5 companies or drugs in one parallel call, with explicit example phrases ('X vs Y', 'which is bigger', 'rank these companies'). It distinguishes itself from sequential lookups, making the purpose unmistakable.

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 says 'ALWAYS PREFER over sequential single-pack lookups when comparing entities.' It provides guidance on when to use (comparing entities) and what data each type returns. It lacks explicit when-not-to-use scenarios but is still very useful.

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