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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds a genuine behavioral disclosure: an Unknown quote-reference setting does not establish automatic reference generation. This is exactly the kind of edge-case behavior an agent couldn't infer from annotations or schema, and it prevents misinterpretation of returned settings. The includeRaw parameter description also clarifies operator versus customer-facing use, which is behavioral context beyond basic safety.

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?

Two sentences, front-loaded with the primary purpose, followed by a concise behavioral caveat. No wasted words. Slightly more could be packed in about related tools, but the length is appropriate for a simple read operation.

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?

For a read-only tool with no output schema and a 100% schema-covered parameter set, the description covers the essential behavior and the critical edge case (Unknown reference settings). The connectionRef reuse guidance lives in the schema, so it's not missing. It doesn't describe the return shape, but with no output schema and a simple settings lookup, the main risk — misinterpreting Unknown as automatic generation — is explicitly addressed.

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 100%, so the schema already documents all three parameters well. However, the description adds value on the connectionRef parameter by explaining the opaque nature, session-id rotation behavior, and reuse guidance — details not present in the schema's terse 'Opaque Red connection reference' text. The includeRaw guidance about customer-facing responses is also in the schema, so the description's contribution is mainly around connectionRef semantics, which pushes it above baseline 3.

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 ('Returns') and resource ('quote and transaction reference settings'), clearly distinguishing this from sibling tools like brc_get_company_processing_settings or brc_list_company_settings. It doesn't explicitly name a sibling, but the resource scope ('reference settings') is specific enough. The second sentence about Unknown quote-reference settings adds meaningful behavior detail.

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?

The description implies when to use it (when you need quote/transaction reference settings), but does not explicitly say when not to use it or name alternatives like brc_get_company_processing_settings or brc_check_transaction_settings. The sibling list includes several settings-related tools, so some exclusion guidance would help, but the resource naming is fairly clear.

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