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

Annotations only supply destructiveHint=true with no explanation. The description adds real behavioral context beyond that: setting state to disabled halts tracking and earning, and the change is reversible ('set it back to active to undo'). It stops short of describing partial-vs-full update behavior or auth requirements, but it meaningfully enriches the safety picture.

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 dense, front-loaded sentences covering fields and consequences, followed by an endpoint mapping. The 'Rewardful: PUT /v1/affiliates/:id' line is mild filler but useful for endpoint mapping; overall there's little waste.

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 tool with 10 parameters, only 1 required and no output schema, the description is decent but leaves a key gap: it doesn't state whether omitted fields are left unchanged or cleared (partial vs. full replace), which directly affects how an agent should call a PUT-style update. Auth/permission requirements are also 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%, so baseline is 3, but the description adds meaning the schema doesn't: noting that setting campaign 'moves them' and that 'payout emails' map to the wise_email/paypal_email fields. That is incremental semantic value on top of well-documented parameters.

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?

Specific verb ('Change') plus resource ('an affiliate's') with an explicit enumeration of mutable fields (name, email, payout emails, notifications, campaign, state). This clearly separates it from the sibling create/get/list affiliate tools.

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 implied by the field list and by the state semantics, but the description never states prerequisites (e.g., needing an existing affiliate_id) or when to prefer create_affiliate versus this update. No explicit alternatives are named.

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