call_rpc

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

With no annotations, the description carries full burden. It discloses that the tool uses service_role and bypasses RLS, which is critical behavioral information. However, it does not mention error handling, return format, or rate limits, so it is not fully comprehensive.

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 two sentences with no unnecessary words, efficiently conveying the core functionality and key security implication. It is well front-loaded.

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 function call tool with no output schema, the description is moderately complete. It explains what the tool does and a key behavior (privilege escalation), but omits details about return values, error handling, and authentication beyond service_role.

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 coverage is 100%, so the baseline is 3. The description adds minimal additional meaning beyond the schema, simply restating that fn is a function name and args are named arguments. No extra constraints or context are provided.

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 calls a Supabase PostgreSQL function (RPC) via the REST API, with specific verb+resource. The mention of using service_role and bypassing RLS distinguishes it from siblings like execute_sql and execute_rls_sql.

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 implies the tool is for functions requiring elevated privileges due to service_role and RLS bypass, but it does not explicitly state when to use this tool versus alternatives like execute_sql or query_db. No when-not or exclusion criteria are provided.

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