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

Annotations already establish readOnly, idempotent, non-destructive and closed-world, so the bar is lower; the description adds genuinely new behavior: the null-request default to a shipped synthetic example, the permission prerequisite for user data, and the explicit caveat that rights_confirmed does not verify a licence. That caveat is important, since it tells the agent the flag is an attestation rather than a validation step.

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 short sentences, front-loaded with what the tool computes and followed by the two operational rules. Each sentence carries information, with only mild awkwardness in the phrasing of the omit-request sentence.

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?

An output schema exists, so return values need not be described, and the permission caveat covers the main safety concern. However, for a tool with a complex nested request and no schema descriptions, the definition leaves the relationship between data_mode ('synthetic' vs 'user-licensed'), source, and rights_confirmed unexplained.

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 description coverage is 0% and the single request object is deeply nested (as_of, currency, source, data_mode, underlyings, positions with 11 fields each), yet the description explains only rights_confirmed and the omit-request convention. It never clarifies what source, data_mode values, or currency mean in context, so it fails to compensate for the documentation gap.

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 first sentence names the exact computation (cash delta, gamma, vega, theta, rho) and the exact input domain (a book of linear positions and European options), so an agent knows precisely what it produces. It does not explicitly contrast itself with siblings such as risk_derivatives_grid or risk_scenario_scale, which keeps it short of a 5.

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?

It gives concrete when-to-use behavior on both paths: omit the request to run the shipped synthetic example, and for supplied data require permission with rights_confirmed=true. It offers no explicit when-not or named alternative tool, so it stops short of full routing guidance.

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