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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds real value beyond that by enumerating what the response contains (campaign plus the earning sale with charge, refund, tax, referral, customer and affiliate), which is the only place this return shape is documented since there is no output schema.

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 compact sentences: the payload summary is front-loaded and the Rewardful endpoint reference is a useful trailing anchor. Nothing is padded.

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 single-resource read with no output schema, the description partially compensates by sketching the returned fields, which is the key missing structured information. It stops short of describing error behavior for an invalid or unknown id.

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 commission_id parameter is fully documented in the schema as a UUID. The description only restates that lookup is by id, adding no syntax or format detail beyond the schema, so the baseline of 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 and resource ('Fetch a single commission by id') and scopes it to one record, which implicitly separates it from the sibling list_commissions. It never names that sibling explicitly, so it falls short of the highest tier of sibling differentiation.

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?

Usage is only implied: 'by id' suggests you already hold a commission UUID, versus listing/querying for one. There is no explicit when-to-use statement and no named alternative such as rewardful_list_commissions.

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