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

With no annotations, the description carries the full burden and discloses key behaviors: the tool is paid, requires a CIK, and follows a two-step x402 payment flow. It even specifies what the terms include ('amount, asset, network'). It stops short of describing response format or error handling, but the payment and access behaviors are well covered.

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 four sentences and each serves a purpose: purpose statement, requirement, payment workflow, and free alternative. The 'Paid:' prefix clearly separates the payment instructions. Slightly longer than the ideal two-sentence example but no wasted words enough to justify a 4.

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?

Given the tool's complexity (paid two-step flow) and absence of annotations/output schema, the description provides essential context: what it does, the CIK prerequisite, how to pay, and a free alternative. It doesn't detail the return structure, but for invocation purposes it's largely complete. The mention of the pricing tool adds situational context.

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% (base 3), and the description adds value by explaining the x_payment parameter's workflow: omit to receive terms, sign, then pass the signed payload. This clarifies how to use x_payment beyond the schema's basic description. The cik parameter is straightforward and benefits from the explicit prerequisite mention.

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's function: 'What an institutional manager bought, sold, added, and trimmed vs the prior quarter' — a specific verb+resource construction. It distinguishes itself from siblings like manager_holdings by emphasizing period-over-period changes (the 'whale-watch view'), making its purpose unambiguous.

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?

Explicitly states the prerequisite ('Requires the manager's CIK') and provides a detailed usage workflow for the paid tool: call without x_payment to get terms, sign, then call again with x_payment. It also references the free pricing tool as an alternative for price listings. However, it doesn't explicitly mention when not to use this tool or contrast with manager_holdings for current holdings.

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