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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds critical behavioral details: source (SEC EDGAR/XBRL for companies, FAERS for drugs), off-calendar fiscal year handling, and sorting by primary metric. No contradictions.

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 example queries, then follows a clear structure. It is slightly verbose but every sentence adds value. No redundant information.

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?

Despite no output schema, the description explains return format (paired data + pipeworx:// citation URIs) and quantifies efficiency ('replaces 8–15 sequential lookups'). For a comparison tool, it is thorough and covers all necessary aspects.

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%, but the description adds substantial meaning: type enum values are explained with what data they pull, and values parameter is clarified with examples for companies (tickers/CIKs) and drugs (names). This goes beyond the schema's minimal descriptions.

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 common query patterns, then clearly states 'side-by-side comparison of 2–5 companies or drugs in ONE parallel call.' It distinguishes from siblings by explicitly recommending over sequential single-pack 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 gives explicit when-to-use scenarios (comparing entities, 'rank these companies') and prefers this tool over sequential lookups. It also explains the difference between company and drug inputs. Missing explicit when-not scenarios, but the context is strong.

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