supabase_rpc

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

The description adds no behavioral context beyond annotations. readOnlyHint=false and idempotentHint=false already indicate possible mutation, but the description does not disclose potential side effects, permissions required, or return value behavior. 'Call via RPC' is essentially a restatement of the tool's name.

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 a single sentence with no fluff, front-loading the core purpose. However, it is extremely brief and omits critical details, making it under-specified rather than appropriately concise.

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?

This tool invokes arbitrary Postgres functions, which can have varying side effects and return types. With no output schema, the description should explain expected return format and error behavior. It provides none, leaving the agent without essential operational context.

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 input schema already provides descriptions for both functionName and params, achieving 100% schema coverage. The description adds no additional parameter semantics, such as how params should be structured to match the Postgres function's arguments. Baseline 3 is appropriate because schema carries the heavy lifting.

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 ('Call') and the resource ('a Postgres function'), with the mechanism 'via RPC' adding specificity. It distinguishes from common data operations like supabase_query or supabase_insert, but does not explicitly differentiate from supabase_functions_invoke (which likely calls Edge Functions), so it's not fully sibling-distinguishing.

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 instead of alternatives. There is no 'use this when' or 'for standard operations, see ...' context. The description merely states what it does, leaving the agent to infer appropriate usage.

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