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

Annotations only declare readOnlyHint=true, so the description carries the rest of the load and does so well: it discloses the expanded payload (charge, refund and tax amounts, referral, customer, affiliate) that a bare 'get by id' would not convey. No auth or rate-limit details, but for a simple read that is a minor gap.

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?

One front-loaded sentence captures purpose and return content; the trailing endpoint reference (GET /v1/commissions/:id) is mildly redundant but cheap and aids API mapping. No filler.

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 present, the description compensates by enumerating the returned sub-objects, which is exactly what an agent needs to decide whether to call it. Only the discovery path (how to get an id) is left unaddressed.

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 parameter is fully documented as a UUID, so the schema does the heavy lifting. The description's 'by id' adds no format or syntax detail beyond what the schema already provides; 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?

States a specific verb (Fetch) plus resource (a single commission by id) and enumerates the related records returned (campaign, sale, referral, customer, affiliate). This clearly separates it from the sibling rewardful_list_commissions, which returns collections.

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 'by id' phrasing implies this is the direct-lookup tool versus a list/search tool, so the usage context is reasonably inferable. However, it never names rewardful_list_commissions as the alternative for discovery, nor states any precondition for obtaining a commission_id.

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