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

Annotations declare readOnly/openWorld/non-destructive, and the description adds materially beyond them: the credit cost model (1 per company + 1 per event) and the failure-billing behavior (nothing charged if no company matches). For an open-world, metered lookup, that cost and no-match disclosure is exactly the missing context an agent needs.

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?

Three dense sentences with zero filler: purpose first, resolution and filtering second, cost last. Every sentence carries information the agent needs.

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?

With no output schema, the description still conveys the return shape (firmographics, investors, chronological event list) and the cost implications. Nothing essential for correct invocation 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 already 100%, so the baseline is 3; the description adds value by explaining that any one of four identifiers can resolve the company and that include defaults to all event kinds with per-event credit cost. It stops short of stating precedence when multiple identifiers are supplied.

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 ('Return one company's timeline') and enumerates exactly what the payload contains: firmographics, investors, and chronological funding/acquisition/exec/hiring events. This clearly distinguishes it from narrower siblings like funding_events, acquisitions, and exec_moves.

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?

Gives concrete invocation guidance: resolve by id, domain, name, or LinkedIn URL, and select event kinds via include (default all). It implies the aggregation use case versus the single-kind siblings but never explicitly routes the agent to those alternatives or states when it should not be used.

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