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

Annotations already declare readOnlyHint=true, so the description's 'Get' aligns but adds no further behavioral context (e.g., whether earnings are cumulative, filtered by date). The description is adequate but minimal; with annotations, it meets the baseline without adding extra value.

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?

A single sentence with no superfluous words. The description is efficiently front-loaded with the essential information.

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?

Given zero parameters, annotations that indicate read-only safety, and no output schema, the description is mostly complete for a simple retrieval tool. However, it could clarify what 'earnings' includes (e.g., total to date, pending amounts), but the low complexity warrants a high score.

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?

No parameters exist, so schema description coverage is 100% (trivially). The baseline is 3 per rules; the description adds no parameter info, which is acceptable since there are none to document.

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 tool retrieves earnings for the authenticated user's referral code, specifying both the verb 'get' and the resource 'earnings for referral code'. This distinguishes it from siblings like 'get_referral_code_details' (which likely returns code info) and business/community-specific earnings 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?

No guidance on when to use this tool versus alternatives such as 'get_business_referral_reward_summary' or 'get_community_referral_reward_summary'. The agent must infer context from the name alone, which may lead to incorrect tool selection.

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