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

Annotations already indicate readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds valuable behavioral context: correct handling of off-calendar fiscal years, sorting by primary metric, and return of paired data with citation URIs. This goes beyond what annotations provide.

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 trigger phrases and each sentence adds value. However, it is somewhat lengthy and could be slightly more concise without losing information.

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?

Despite no output schema, the description explains the return format (paired data + URIs) and covers type-specific behavior, data sources, and efficiency gains (replacing 8-15 lookups).

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?

With 100% schema coverage, baseline is 3. The description adds significant meaning: explains data sources for each type (SEC EDGAR/XBRL for company, FAERS for drug), clarifies parameter formats (tickers/CIKs vs names), and discusses limits and sorting behavior.

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's function: side-by-side comparison of 2-5 companies or drugs in one parallel call. It uses specific verbs like 'compare' and provides example queries, distinguishing it from sequential lookups (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?

Explicitly states to 'ALWAYS PREFER over sequential single-pack lookups' and provides example queries. The description gives clear context on when to use this tool vs alternatives, such as entity_profile.

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