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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, so the description does not need to repeat that. It adds valuable behavioral details: data sources (SEC EDGAR/XBRL for companies, FAERS for drugs), handling of off-calendar fiscal years, sorting by primary metric, and returning citation URIs.

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 concise and well-structured, using example queries to introduce the purpose, then explaining data sources and behavior. Every sentence adds value, with no redundant or vague phrasing.

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 complexity of comparing entities with multiple data sources, the description is comprehensive. It covers what data is returned (paired data + citation URIs) and addresses edge cases like off-calendar fiscal years. No output schema exists, but the description sufficiently explains the return format.

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 significant meaning beyond the schema. It explains that for type='company' pulls revenue, net income, cash, long-term debt, and handles off-calendar fiscal years. For type='drug' pulls FAERS adverse-event counts, FDA approval counts, and active trial counts. It also clarifies that values are tickers/CIKs for companies and drug names for drugs.

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 explicitly states the tool performs side-by-side comparisons of 2-5 companies or drugs in a single parallel call, using example phrases like 'Compare X and Y' and 'head to head'. It distinguishes from siblings by emphasizing that it replaces 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 provides strong usage guidance with example phrases and explicitly states 'ALWAYS PREFER over sequential single-pack lookups when comparing entities'. However, it does not explicitly mention limitations or when not to use the tool, such as for comparisons of more than 5 entities.

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