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

The description reveals behavioral traits beyond annotations: it discloses data sources (SEC EDGAR/XBRL, FAERS), explains handling of off-calendar fiscal years, and notes results are sorted by primary metric. Annotations already indicate readOnlyHint and idempotentHint, and the description adds context without contradiction.

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 a single, front-loaded paragraph that starts with example queries. It is dense but efficient, covering many details without unnecessary words. Could be slightly more structured (e.g., bullet points) but still earns a 4 for clarity and brevity.

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 complexity (two entity types, multiple data sources, up to 5 entities), the description covers essential aspects: what data is returned (paired data + citation URIs) and how it replaces many lookups. No output schema exists, so the description adequately explains returns.

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 adds meaning by explaining the 'type' enum (company/drug) and the 'values' format (tickers/CIKs for company, drug names). It also provides context on what data is retrieved for each type, enhancing understanding beyond schema definitions.

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 provides side-by-side comparison of 2-5 companies or drugs. It includes example queries like 'compare X and Y' and explains the data pulled for each type. It distinguishes itself from sequential single-pack lookups, matching the 'specific verb+resource' criterion perfectly.

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,' providing clear guidance on when to use this tool. It also includes example queries and specifies the number of entities (2-5), covering both when and why to use it effectively.

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