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

The description explains that for companies it pulls financial data from SEC EDGAR/XBRL and mentions off-calendar fiscal year handling. For drugs it pulls FAERS, FDA, and trial data. This adds significant context beyond the annotations (readOnlyHint, etc.). 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 well-structured with trigger phrases upfront and clear entity-specific details. It is slightly verbose but every sentence adds value. Could be trimmed slightly without losing clarity.

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 complexity of comparing two entity types with different data sources, the description covers all necessary context. It mentions data sources, handling of fiscal years, result format (paired data + URIs), and provides a helpful efficiency estimate (replaces 8-15 sequential lookups). No output schema, but description adequately describes returns.

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?

The description adds meaning beyond the input schema by explaining what each type ('company' vs 'drug') fetches and what values to provide (tickers/CIKs for company, names for drug). It also mentions result sorting by primary metric. Since schema coverage is 100%, the baseline is 3, but the description adds substantial value.

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 that the tool performs side-by-side comparisons of 2-5 companies or drugs in one parallel call. It provides example query phrases and distinguishes from sequential single-entity 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 explicitly states to always prefer this tool over sequential single-entity lookups when comparing entities. It also gives context for when to use it and what entity types are supported.

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