Inspect table schema by listing column names, types, and nullability before composing SQL queries.
Show the columns of one table (name, type, nullable). Use before writing SQL.
| Name | Required | Description | Default |
|---|---|---|---|
| table_name | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It discloses a non-mutating 'show' operation and specifies the exact output fields, making the tool's behavior predictable. It does not discuss error conditions or permissions, but for a simple introspection tool this is sufficient.
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?
Two short sentences with no filler. The core purpose and output are front-loaded, and the usage guidance is added as a separate sentence. Every word earns its place.
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 single-parameter tool with an output schema, the description covers what the tool does, what it returns, and when to use it. No critical information is missing for an agent to invoke it correctly.
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 description must clarify the one parameter. It does so by identifying table_name as the table whose columns are shown. Since the parameter title is already 'Table Name' and the description ties it to the action, the semantic gap is mostly filled.
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 states a specific action and resource: 'Show the columns of one table' with explicit output details (name, type, nullable). This clearly distinguishes it from siblings like list_tables and run_query, and the 'one table' scope separates it from broader schema tools.
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 gives explicit context for when to use the tool: 'Use before writing SQL.' It does not mention alternatives or exclusions relative to get_schema, but the clear use case is enough for an agent to decide when it applies.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.