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

Annotations already declare readOnlyHint and idempotentHint, and the description adds useful behavioral context about cost and payment: 'Premium API. Cost: $0.25 USDC via x402.' This is material information for an agent deciding whether to invoke the tool exactly as written. It does not contradict 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 two short sentences with no wasted words, front-loading the core function before the cost detail. Every clause adds useful information for selection or invocation.

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 simple one-parameter read-only lookup with high schema coverage and safety annotations, the description is nearly sufficient. It names the key data categories and the premium cost, but it does not describe return format, page limits, or auth details; these are minor given the low complexity.

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 schema covers the single parameter comprehensively with 'lookup' described as 'Private company name' and an example ('Anthropic'). The description adds no parameter-specific detail beyond the overall scope, so the schema carries the semantic weight; 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?

The description uses a specific verb ('Retrieve') and names a concrete resource ('private company deal intelligence') followed by illustrative data categories such as funding rounds, valuations, investors, M&A activity, and ownership changes. This makes the tool's purpose clear, though it does not explicitly distinguish itself from sibling tools like parent_company_info or business_info.

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 implies when to use the tool—when you need private company deal data—but it provides no explicit alternatives, exclusions, or comparison to other tools. There is enough context to infer usage, but no direct guidance on choosing between this and similar sibling tools.

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