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

Annotations indicate read-only, open-world, idempotent, non-destructive. Description adds details: for companies, pulls latest 10-K data from SEC EDGAR/XBRL with correct fiscal year handling; for drugs, pulls FAERS adverse events, FDA approvals, trial counts. Results sorted by primary metric. 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?

Front-loaded with trigger phrases and core function. Packs much information into one sentence but could be slightly more structured for readability. Still efficient with minimal waste.

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 and no nested objects or output schema, description covers entity types, data sources, sorting, and citation URIs. Output format could be more explicit (e.g., structure of paired data), but overall complete for expected use.

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 100% with descriptions. Description enriches by explaining what data each type returns (company vs drug), gives examples for values (tickers, drug names), and notes off-calendar fiscal year handling. Adds significant 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?

Description clearly states tool does side-by-side comparison of 2-5 companies or drugs in one parallel call, with explicit trigger phrases like 'Compare X and Y' and 'X vs Y'. It distinguishes from siblings by recommending over sequential single-pack lookups, addressing sibling tools like entity_profile.

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?

Provides explicit when-to-use guidance: comparison, ranking, head-to-head. Says 'ALWAYS PREFER over sequential single-pack lookups' and mentions replacing 8-15 lookups, giving clear context for use cases.

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