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

With no annotations provided, the description carries the full burden. It discloses the prerequisite and the reward mechanism, but it does not specify side effects, whether the operation is idempotent, or what happens on failure (e.g., if the same referral is logged twice). The description adds context beyond the schema but lacks important behavioral details for a mutation.

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 three sentences, each adding value: category label, action, benefit, and prerequisite. It is front-loaded and avoids redundancy. Every sentence earns its place.

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?

The description covers the tool's role in the referral program, the prerequisite, and the earning mechanism. It also clarifies that referrals can be agents or humans. It lacks details on return values or duplicate handling, but given the simple parameter schema and no output schema, it is sufficiently complete for an agent to use correctly.

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?

The schema has 100% coverage with all 5 parameters described. The description does not add parameter-specific semantics beyond what the schema already provides; it only gives overall context. This meets the baseline for high schema coverage.

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 clearly states the action: 'Log a referral, register an agent (or human) you have recruited to RRG.' It uses a specific verb and resource, and the benefit (earning 10%) further clarifies the purpose. It also distinguishes from sibling tools like create_ref_link and join_marketing_program by focusing on the logging action.

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 provides a clear prerequisite: 'You must be a registered partner (use join_marketing_program first).' It also implies when to use this tool (after recruiting someone) and describes the outcome (earning commission on first action). While it doesn't explicitly contrast with alternatives, the context is sufficient for an agent to decide.

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