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

Annotations already cover the read-only, idempotent, non-destructive profile, and the description adds substantive context beyond them: per-name cost (0.0012 USDC), total (0.03 USDC), the 15-credit API-key path, the first-5-free-per-day allowance, and the shape of the result (top 3 matches with positions and status). What it omits is what happens when both api_key and payment are available, or any rate limit beyond the free tier.

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 trigger condition is front-loaded in the opening clause, and every subsequent phrase carries load (pricing, output shape, billing fallback). The pricing and free-tier detail is dense but not redundant, though it slightly crowds the core selection signal.

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 compensates by describing the return value, and it also covers both billing paths and the free daily allowance, which an agent needs before invoking a paid tool. The remaining gap is the precedence between api_key and x402 payment, which the schema only hints at.

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 the baseline would be 3, but the description adds a genuine parameter constraint the schema lacks: the upper bound of 25 names per call. The ';' separator and the api_key sourcing are already documented in the schema.

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 states a specific verb and resource: screen a list of up to 25 names for PEP status in one call, returning the top 3 matches with positions and status. The batch scope ('list', 'in one call') clearly separates it from the single-name sibling pep_screen without needing to open either 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?

It gives a concrete when-to-use cue ('For customer-base and CRM re-screening') and the precondition of up to 25 names. It stops short of explicitly routing single-name lookups to pep_screen, so the alternative is implied rather than named.

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