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

The description adds significant value beyond annotations: it details data sources (SEC EDGAR/XBRL for companies, FAERS for drugs), explains how off-calendar fiscal years are handled, mentions sorting by primary metric, and specifies output format (paired data + pipeworx:// citation URIs). No contradictions with annotations (readOnlyHint, openWorldHint, idempotentHint, destructiveHint).

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 somewhat lengthy but every sentence provides valuable information. It starts with example queries to quickly convey the tool's use case, then explains behavior, preferences, and data sources. No filler or repetition.

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's complexity (2 parameter types, different data sources, no output schema), the description thoroughly explains what data is returned per entity type, how results are sorted, and the fact that it replaces multiple sequential lookups. All essential aspects are covered.

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 covers 100% of parameters, but the description adds critical context: for type 'company' it pulls financial metrics and lists them; for type 'drug' it pulls FAERS counts, FDA approvals, trials. This goes beyond the schema's enum descriptions, enriching parameter meaning.

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 purpose: 'side-by-side comparison of 2–5 companies or drugs in ONE parallel call.' It uses specific verbs (compare) and resources (companies/drugs), and distinguishes itself from siblings like 'entity_profile' which likely handles single entities.

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 says 'ALWAYS PREFER over sequential single-pack lookups when comparing entities,' providing clear guidance on when to use this tool. While it doesn't explicitly state when not to use it, the preference is strongly conveyed, and alternatives are implied (e.g., entity_profile for single lookups).

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