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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, but the description adds substantial context: data sources (SEC EDGAR/XBRL, FAERS), handling of off-calendar fiscal years, sorting by primary metric, return format with citation URIs, and the efficiency claim of replacing 8–15 lookups. Enhances the agent's understanding 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 dense but not overly long; the initial trigger phrase list is useful for matching user intent, and each sentence contributes functional information. Slightly verbose in the trigger examples, but earns its place for an AI agent.

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 no output schema, the description explains the return type ('paired data + pipeworx:// citation URIs') and sorting behavior. It covers the two parameter types, data sources, and edge-case handling (off-calendar fiscal years). Minor gaps include the exact structure of 'paired data', but this is adequate for invocation.

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%, so baseline is 3, but the description adds meaningful nuance to the 'type' parameter by specifying what data each entity type pulls (e.g., 'company' pulls latest 10-K revenue, 'drug' pulls FAERS counts). This goes beyond the schema's simple 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?

Description clearly states a specific verb+resource: 'side-by-side comparison of 2–5 companies or drugs in ONE parallel call.' It also includes trigger phrases and explicitly contrasts with sequential single-pack lookups, distinguishing it 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?

Provides explicit guidance: 'ALWAYS PREFER over sequential single-pack lookups when comparing entities.' Defines use cases for company vs drug types with concrete examples. Does not explicitly mention when *not* to use it (e.g., for single entity lookups), but the emphasis on comparison makes this implicit.

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