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

Annotations already declare readOnly, idempotent, and non-destructive, and the description partly restates that ('Read-only and idempotent; no side effects'). It goes beyond annotations by disclosing error behavior ('structured job_not_found error' on unknown job_id), the freshness/dynamic nature of the terms, and the quote-vs-payment semantic.

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?

Front-loaded with the core purpose and the trigger condition, then return fields, error behavior, and an example. Mostly efficient, though 'Read-only and idempotent; no side effects' is redundant with the annotations and adds length without new information.

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?

A single required, fully specified parameter, complete annotations, and an output schema mean the definition need not explain return values. The description still covers purpose, trigger, error case, and semantics, leaving nothing an agent needs to call it correctly.

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% and the single job_id is fully documented with pattern and source. The description reinforces the source of the id ('returned by aftersearch_resolve') and adds the 'exact job only' scoping, but adds little syntax or format detail beyond the schema, so the baseline of 3 holds.

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 (Return) and resource (fresh x402 PAYMENT-REQUIRED terms for one immutable job), including the exact fields returned (USDC price, pay_to, network, asset). It is clearly distinguishable from siblings like aftersearch_accept and aftersearch_resolve.

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 names the precondition ('when an agent holds a job_id') and the decision context ('needs the current USDC price and payment instructions before deciding to pay'), and contrasts with the payment step by noting 'a 402 challenge is a quote, never payment'. The example ties it to aftersearch_resolve as the job_id source.

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