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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive behavior, so the safety profile is covered. The description adds genuinely useful context beyond annotations: the $0.25 USDC x402 cost and the concrete returned fields, which an agent needs before committing to a paid call.

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?

Front-loaded with purpose and output fields, then usage, then cost. The purpose-fragment list ('For sales prospecting...') is slightly listy but each clause adds targeting value; nothing is wasted.

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?

Though there is no output schema, the description enumerates returned fields, discloses cost, and covers both parameters, so an agent has everything needed to decide and call correctly. Nothing material is missing.

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 both the combined 'lookup' string and the enum-constrained 'language' are fully documented. The description restates the company+title input with an example but adds little beyond the schema's own example and language enum, so baseline 3 applies.

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?

States a specific verb and resource ('Executive and leadership lookup') and enumerates exactly what it returns: name, title, company website, LinkedIn URL, and biography source URL. That output shape distinguishes it from siblings like business_info or x_profile without opening any schema.

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 clear when-to-use context ('sales prospecting, lead generation, account research, and finding decision makers') and an example input. However, it names no exclusions or alternative sibling tools for overlapping needs such as business_info or buying_signals.

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