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

Annotations already mark read-only, idempotent, non-destructive, but the description adds valuable context: data sources (SEC EDGAR/XBRL, FAERS), fiscal-year handling for companies, sorting by primary metric, and citation URIs in the response. This goes well beyond the 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 detailed but every sentence delivers unique information. It is front-loaded with usage examples and prioritization rule, then provides data source specifics and output characteristics. There is no filler or repetition.

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 complexity and lack of output schema, the description covers return format (paired data + citation URIs), sorting behavior, data source details, and edge cases (off-calendar fiscal years). It is complete enough for an agent to invoke correctly without additional lookup.

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%, so parameters are already documented. The description adds meaning by explaining what each type parameter does (company vs drug) and what 'values' should contain (tickers/CIKs vs drug names), including examples. This elevates beyond the baseline schema.

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 states a specific action: side-by-side comparison of 2–5 companies or drugs in a single parallel call. It clearly distinguishes from siblings like entity_profile by mentioning 'replaces 8–15 sequential lookups' and uses a specific verb ('compare') with defined resource types.

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?

Provides explicit when-to-use guidance with trigger phrases ('X vs Y', 'which is bigger', 'rank these companies') and an explicit 'ALWAYS PREFER over sequential single-pack lookups' instruction. This makes the intended usage unambiguous relative to alternatives.

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