Supabase: Get user by email

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

The readOnlyHint=true annotation already covers the safety profile, so the description only needs to add context. It adds none: nothing about behavior when the email is not found (error vs empty result), whether the match is exact or case-insensitive, or whether multiple/duplicate emails are possible.

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 with the resource and lookup key front-loaded, so there is no padding. The "[UNIFIED]" prefix is internal tagging noise that costs a little clarity but does not obscure meaning.

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 simple two-parameter lookup this could be adequate, but with zero schema descriptions the definition leaves one required parameter (site) undocumented and says nothing about not-found behavior. An agent cannot reliably construct the call from this text alone.

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% for two required parameters. The description clarifies only that the string is an email address; the required "site" parameter is completely unexplained in both the schema and the description, leaving the agent to guess what value to supply.

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 names a specific verb and resource combination ("Find a user") plus the lookup key ("by their email address"), which distinguishes it from the id-based supabase_get_user sibling. It is clear and unambiguous, though it does not explicitly name the alternative it contrasts with.

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?

There is no when-to-use guidance beyond the implicit hint that this is the email-based lookup. The sibling list contains supabase_get_user, and the definition never says which one to pick when you have an email versus an id, nor what happens if no match exists.

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