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

Annotations declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds context: data sources (SEC EDGAR/XBRL for companies, FAERS for drugs), handling of off-calendar fiscal years, and return format (paired data + citation URIs). It does not cover rate limits or errors, but overall adds significant behavioral context.

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, well-structured paragraph that front-loads key trigger phrases. Every sentence contributes value: usage guidance, data sources, sorting behavior, return format, and efficiency claim. No redundant or unnecessary text.

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 + citation URIs) and data sources. It covers entity types, metrics, and sorting. Missing details on error handling or data freshness, but for a 2-param tool it is adequately 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% with brief descriptions. The description adds meaning by mapping type values to specific output metrics (revenue, net income, etc. for company; FAERS counts for drug) and providing example inputs for values (tickers, drug names).

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 explicitly states the tool's purpose: side-by-side comparison of 2–5 companies or drugs in one parallel call. It lists common trigger phrases ('compare X and Y', 'X vs Y', etc.) and clearly distinguishes itself from sequential 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 provides explicit guidance: 'ALWAYS PREFER over sequential single-pack lookups' and details when to use each entity type (company vs drug) with specific metrics (10-K data, FAERS counts). It also explains sorting by primary metric for answering 'largest' queries.

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