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

Despite strong annotations (readOnly, idempotent, openWorld), the description adds rich behavioral context: specific data sources (SEC EDGAR, FAERS), handling of off-calendar fiscal years, sorting by primary metric, and return of paired data with citation URIs. This goes far beyond the annotations.

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 the core purpose and examples, but it's slightly long. Some redundancy exists (mentions side-by-side comparison and also 'replaces 8–15 sequential lookups'), but every sentence contributes useful information. Not as tight as the best examples.

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?

For a tool with no output schema, the description thoroughly covers return format (paired data + citation URIs), data sources, sorting behavior, and entity-type specifics. It answers likely agent questions about what data is returned and how results are ordered, making it highly complete.

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?

Even though schema coverage is 100%, the description greatly enriches parameter meaning: it details exactly what type='company' vs 'drug' retrieves (e.g., revenue, net income, adverse event counts), and gives concrete examples for the values array. This adds substantial value beyond the 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?

The description clearly states the tool performs side-by-side comparisons of 2–5 companies or drugs in a single call, with examples like 'X vs Y' and 'which is bigger'. It distinguishes itself from sequential lookups, making its purpose specific and unambiguous.

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 instructs to 'ALWAYS PREFER' over sequential single-pack lookups when comparing entities, and notes it replaces 8–15 sequential lookups. This gives clear when-to-use guidance, though it doesn't name a specific sibling tool as an alternative.

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