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

Beyond the readOnly/idempotent annotations, the description adds rich behavioral context: data sources (SEC EDGAR/XBRL for companies, FAERS for drugs), handling of off-calendar fiscal years, sorting by primary metric, and return of citation URIs. This goes beyond what annotations provide.

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 well-structured: it opens with trigger phrases, then states the core function, then provides per-type details, then output format. Every sentence contributes actionable information with no filler.

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?

Considering the tool's complexity and lack of an output schema, the description covers input constraints (2–5 entities), data sources, fiscal-year handling, sorting behavior, and output format (paired data + citation URIs). It is fully self-contained for an agent to invoke correctly.

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 significant semantic meaning for the 'type' parameter, detailing exactly what data each entity type retrieves (10-K metrics vs. FAERS/FDA/trial counts). It also clarifies the 'values' parameter with examples and constraints. This exceeds the baseline for high schema coverage.

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 performs 'side-by-side comparison of 2–5 companies or drugs in ONE parallel call.' It specifies a concrete verb and resource, and distinguishes itself from single-entity lookups by noting it 'Replaces 8–15 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?

Explicit guidance is given: 'ALWAYS PREFER over sequential single-pack lookups when comparing entities' and trigger examples like 'X vs Y' and 'rank these companies.' This clearly tells the agent when to use this tool and when not to (i.e., instead of sequential lookups).

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