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

Annotations already indicate readOnlyHint, openWorldHint, idempotentHint, and non-destructive. The description adds significant behavioral context: it pulls from specific data sources (SEC EDGAR/XBRL for companies, FAERS for drugs), handles off-calendar fiscal years correctly, sorts results by primary metric, and returns paired data with citation URIs. No contradiction with 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 a single paragraph but front-loaded with example triggers. Every sentence adds value, though it could be slightly more structured (e.g., bullet points) for easier scanning.

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?

With no output schema, the description adequately explains return structure: paired data + pipeworx:// citation URIs, sorted by primary metric. It also covers data sources and special handling (fiscal years). For a tool with only 2 required parameters and no nested objects, this is very 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?

Schema coverage is 100% and describes both parameters. The description adds meaning beyond schema: it clarifies that for type='company' values should be tickers/CIKs and for type='drug' should be drug names, explains what data is fetched for each type, and reinforces the constraints on array length. This adds significant context.

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 uses specific verbs like 'compare', 'vs', 'head to head' and clearly states it performs side-by-side comparison of 2-5 companies or drugs in one parallel call. It distinguishes from sibling tools like entity_profile which would be used for single entity 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 explicitly advises to 'ALWAYS PREFER over sequential single-pack lookups when comparing entities', providing clear context on when to use. It does not explicitly list alternatives, but the instruction to prefer this over sequential lookups is strong guidance.

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