supabase_upsert

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

With no annotations and no output schema, the description carries the full behavioral burden. It does not state whether matching rows are fully overwritten or selectively merged, what permissions are needed, whether the operation is transactional, or what is returned. Only the vague word 'merge' hints at conflict behavior.

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 front-loaded sentence with no filler; the conflict-key detail is placed at the end where it belongs as an optional modifier. Nothing is wasted.

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 mutation tool with zero annotations, zero schema description coverage, and no output schema, the description is too thin. It omits return behavior, conflict-resolution semantics (overwrite vs merge per column), and permission requirements that an agent needs before invoking a write operation.

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 schema gives no meaning for any parameter. The description rescues on_conflict by defining it as a 'comma-separated conflict key list', a real format detail absent from the schema. It adds nothing about rows (batch shape, partial vs full rows) or table, leaving two of three parameters undocumented.

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 gives a specific verb ('Insert or merge rows'), which conveys the upsert semantics and implicitly distinguishes it from a plain insert by mentioning merging. However, it never names supabase_insert or supabase_update, so an agent must infer the boundary between this tool and those siblings.

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 guidance on when to prefer this over supabase_insert or supabase_update, nor any mention of prerequisites such as the table existing or a unique constraint being present for the conflict key. Usage is implied only by the word 'merge'.

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