Inspect a database table by retrieving its columns—name, type, nullability, and default—along with its indexes to understand schema structure.
Describe a table: columns (name/type/nullable/default) and indexes.
| Name | Required | Description | Default |
|---|---|---|---|
| table | Yes | ||
| schema | No | ||
| connection_id | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. 'Describe' reasonably implies a non-mutating metadata read, and it discloses the shape of what comes back (columns, types, nullability, defaults, indexes), which is useful. It does not cover error behavior for a missing table, permission requirements, or whether indexes are always included.
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 zero filler; the colon-plus-enumeration structure conveys the return payload efficiently.
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?
With no annotations, no output schema, and 0% parameter coverage, the description should do more. It partially compensates by listing returned fields, but leaves the connection_id/schema semantics and read-only guarantees entirely to inference.
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 three parameters — connection_id, table, and the optional schema — are completely undocumented. The description mentions 'table' only implicitly and never explains that schema selects a non-default namespace, which is the most likely source of a failed call.
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?
States a specific verb and resource ('Describe a table') and even enumerates the returned fields (columns with name/type/nullable/default, plus indexes). It is clearly distinct from db_query and db_execute, though it never names a sibling like db_list_tables or mongo_describe_collection to sharpen the boundary.
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 call this versus db_list_tables (discover tables) or db_query (inspect data). Nothing says whether the table must already exist, whether this is the right tool before writing a query, or what to do with the optional schema argument.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.