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

Annotations already mark it read-only/idempotent, and description adds behavioral detail: data sources (SEC EDGAR/XBRL, FAERS/FDA), sort order by primary metric, citation URIs, and off-calendar fiscal year handling. 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?

Description is front-loaded with purpose and trigger phrases, and the additional details (data sources, sorting, citations) earn their keep. It is longer than necessary but each sentence provides actionable context.

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?

For a 2-parameter tool with no output schema, the description fully specifies inputs, outputs, data provenance, sorting, and citation format. It also addresses edge cases like off-calendar fiscal years, making it self-sufficient despite missing output schema.

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 covers both parameters (100%), but description enriches semantics by explaining what each type pulls (10-K metrics vs FAERS/FDA/trial counts) and value constraints (2–5 tickers/names). This goes beyond schema's basic 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 opens with explicit trigger phrases and states 'side-by-side comparison of 2–5 companies or drugs in ONE parallel call.' It clearly distinguishes the tool from siblings by noting it replaces sequential single-pack lookups and is preferred for comparisons.

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?

Description includes explicit 'ALWAYS PREFER over sequential single-pack lookups when comparing entities' and provides type-specific contexts (company vs drug). This is direct guidance on when to choose this tool over alternatives.

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