Supabase: List user factors

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

Annotations already declare readOnlyHint=true, so the non-destructive read profile is covered. The description adds the useful detail that phone factors are included alongside TOTP, but says nothing about privilege requirements, behavior for unknown user_id, or the response shape for a user with no enrolled factors.

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 short sentence that front-loads the action and resource, with the returned factor types in parentheses. Nothing is padding; there is no wasted clause.

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 two-parameter read-only listing tool with annotations covering safety, the description is close to sufficient, but the unexplained site parameter and the absent auth/privilege context leave real gaps. A one-clause note on which Supabase instance site refers to would make it complete.

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 description coverage is 0%, so the description must carry the semantics — and 'for a user' does anchor user_id as the target user whose factors are listed. However, the site parameter is left entirely unexplained with no hint that it selects the Supabase project/instance, so half the parameters remain uninterpretable from this text.

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 — lists MFA factors — and narrows scope to the factor types returned (TOTP, phone) for a single user. That is enough to separate it from supabase_list_users or supabase_delete_user_factor, though it never names a sibling or explains the '[UNIFIED]' prefix.

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 gives no when-to-use guidance, no prerequisites, and no alternatives. It does not say whether this requires admin/service-role credentials or whether it must be preceded by supabase_get_user to confirm the user exists, so the agent must infer call conditions entirely.

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