update_user_referrer

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

No annotations, but description thoroughly discloses idempotent upsert, side effects (no creation of referral_code_uses), auth requirements (service_role project API key only), and flow steps.

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?

5-6 sentences, each providing distinct value: action, idempotency, side-effect disclaimer, alternative, auth, and a concrete example. No redundancy.

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?

Covers the essential aspects: action, flow, auth, and an example. Lacks details on response/error schema but overall sufficient given the complexity.

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 covers 4/8 parameters with descriptions. Description provides context for project_api_key (env variable fallback) and an example covering identifier parameters, compensating for the remaining half.

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?

Description clearly states it creates or overwrites user_referrers via idempotent upsert, and distinguishes from sibling use_referral_code by noting it does not create referral_code_uses.

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?

Explicitly states when to use (admin override) and when to use alternative (use_referral_code for real code redemption). Also explains required auth and dry_run/confirmed flow.

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