Retrieve columns, constraints, and indexes for a table or view, and inspect sequence or extension details.
Show columns, constraints and indexes of a table or view, or details of a sequence or extension.
| Name | Required | Description | Default |
|---|---|---|---|
| object_name | Yes | Object name | |
| object_type | No | Object type: table, view, sequence or extension (default table) | |
| schema_name | Yes | Schema name |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered elsewhere. The description contributes the useful fact that output is structural metadata per object type, but it is vague for sequences/extensions ('details') and says nothing about failure behavior for missing objects.
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 sentence that front-loads the retrieved fields and then branches by object type. No filler, no redundancy, nothing to trim.
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 three-parameter read tool with full annotation and schema coverage, the description covers what matters: what metadata comes back per object type. The only loose end is that 'details' for sequence/extension is not unpacked, but that is a minor gap rather than a blocking one.
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 100%, so all three parameters are already documented, including the object_type default of table. The description adds no syntax, casing, or qualification guidance beyond restating the object kinds, so it sits at the baseline.
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 (show) and enumerates exactly what is retrieved for each object kind: columns, constraints and indexes for tables/views, and details for sequences/extensions. That distinguishes it clearly from list_objects, though it never names the sibling explicitly.
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?
Usage is only implied: use this when you already know the object and want its structure, versus list_objects when you don't. There is no explicit when-to-use statement, no mention of prerequisites (e.g. that the object must exist), and no comparison to siblings like execute_sql or list_objects.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.