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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive. The description adds significant behavioral context: data sources (SEC EDGAR/XBRL for companies, FAERS/clinical trials for drugs), how fiscal years are handled, sorting by primary metric, and return format with citation URIs. No contradiction with 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 front-loaded with example queries and key advice. While it is somewhat long, every sentence adds value (purpose, data sources, formatting, sorting, comparison benefit). A slight reordering or trimming could improve conciseness, but it is well-structured for readability.

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 tool's moderate complexity (2 params, no output schema), the description covers purpose, usage, data sources, parameter semantics, and expected behavior. It explains return format (paired data + citation URIs) and sorting, which compensates for lack of output schema. However, it could mention any limitations or error conditions.

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 provides rich additional meaning: explains what data each 'type' fetches (e.g., 'company' pulls revenue, net income, cash, long-term debt), how to format values (tickers/CIKs for company, drug names for drug), and constraints (2-5 items). This goes well 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 clearly states the tool performs side-by-side comparisons of 2-5 companies or drugs in a single call, using verbs like 'compare', 'rank', and specifying the resource (entities). It distinguishes itself from potential siblings like 'entity_profile' by emphasizing parallel vs 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 explicitly says 'ALWAYS PREFER over sequential single-pack lookups when comparing entities', providing clear guidance. It also notes it replaces 8-15 sequential lookups, implying efficiency. However, it does not explicitly list when NOT to use it or mention specific sibling tools as alternatives.

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