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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: total_cost is the all-in price, currency defaults to USD, untested records over 500 sats warrant a user warning, and paused Lightning payments surface paymentsPaused and retryAfter in the result.

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 short and front-loaded with the output-fields sentence, but it reads as disconnected fragments ('total_cost is the all-in price only. Default USD.') and mixes pricing semantics with payment-state handling. Each sentence carries information, but the structure is choppy and the key purpose is buried.

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-value documentation is not required, and annotations cover safety. The description still supplies the non-obvious bits an agent needs: pricing semantics, the untested-over-500 warning, and the paused-payment result fields; only the sibling routing remains thin.

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 schema already documents all four parameters, including currency enum, quantity caps, and usd_per_million. The description only reiterates 'Default USD,' adding no syntax or semantics beyond the schema, so the 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?

It states that it retrieves 'Parameter schema, schema confidence, and exampleCall for one SKU,' which identifies the resource but describes output fields rather than the action's purpose (a detail/pricing lookup for a catalog item). A reader can infer this is the read-only detail tool for a single SKU, but the verb and overall intent are vague and it does not explicitly differentiate itself from siblings like quote or search_catalog.

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?

There is a conditional rule tied to the buying flow ('If the record is untested and totalSats is over 500, tell the user before buying'), which gives some usage context. However, there is no explicit statement of when to use this tool versus quote, search_catalog, or report_sku, so the routing guidance is only implied.

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