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

Annotations declare read-only, open-world, idempotent, non-destructive behavior. The description adds rich behavioral context: data sources (SEC EDGAR/XBRL, FAERS), off-calendar fiscal year handling, sorting by primary metric, and return of paired data plus citation URIs. 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 dense and front-loaded with usage triggers, then explains mechanics and data sources. Every sentence adds value, though 'Replaces 8–15 sequential lookups' is somewhat redundant and the FISCAL-year example adds length. Still, overall it is well-organized and appropriately sized.

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 tool with no output schema, the description explains input scope, data sources, sorting behavior, and output (paired data + citation URIs). It does not fully specify the return structure or pagination, but it provides enough context for an agent to select and invoke the tool 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?

The input schema already covers parameters with 100% description coverage. The tool description adds valuable meaning by explaining what each type ('company' vs 'drug') pulls and clarifying that values are tickers/CIKs or drug names, enhancing the 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 clearly states the tool performs side-by-side comparison of 2–5 companies or drugs in one parallel call, with explicit trigger phrases and scope (companies or drugs). It distinguishes from sequential single-pack lookups, making its purpose and differentiation clear.

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 provides explicit trigger phrases and states 'ALWAYS PREFER over sequential single-pack lookups when comparing entities,' giving clear when-to-use guidance. However, it does not explicitly name the alternative tool (e.g., entity_profile) or state when not to use this tool, so it falls short of a full 5.

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