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

Beyond the annotations (readOnlyHint, openWorldHint, idempotentHint, destructiveHint), the description details exactly what data is pulled per type: latest 10-K financials for companies (with off-calendar FY handling) and FAERS/FDA/trials for drugs. It also mentions result sorting and citation URIs, providing full disclosure of behavior.

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 dense paragraph that effectively front-loads the purpose with examples. It conveys a lot of information without verbosity, though it could be slightly more structured (e.g., separate sections for company vs drug).

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?

Without an output schema, the description explains what is returned (paired data + pipeworx:// citation URIs) and the efficiency gain (replaces 8-15 lookups). It covers key aspects but could optionally mention pagination or sorting details more explicitly.

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?

Although the schema covers all parameters, the description adds meaning by explaining that 'values' expects tickers/CIKs for company and drug names, and specifies the 2-5 range. It also clarifies that the 'type' parameter determines the data source, adding value beyond the enum description.

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 starts with clear example queries and states 'side-by-side comparison of 2–5 companies or drugs in ONE parallel call.' It explicitly distinguishes from sequential single-pack lookups, making the tool's purpose unmistakable and setting it apart from 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?

The description provides explicit guidance to 'ALWAYS PREFER over sequential single-pack lookups when comparing entities' and gives example queries (compare, rank, head-to-head). It does not explicitly state when not to use it, but the context implies it is for comparisons of 2-5 entities, leaving some ambiguity.

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