Inspect MongoDB indexes and document fields to understand schema-less data. Provide database and collection names to reveal collection structure before querying.
Inspect MongoDB indexes; MongoDB documents need not share a schema.
| Name | Required | Description | Default |
|---|---|---|---|
| database | Yes | ||
| collection | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
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=true and destructiveHint=false, so safety is covered. The note that MongoDB documents need not share a schema is genuinely useful context for interpreting results, but it is the only behavioral detail offered and says nothing about scope, cost, or sampling 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?
Two brief clauses with no waste, but the semicolon-joined second clause about schemas is not clearly tied to the first and reads as filler rather than front-loaded purpose.
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?
An output schema exists, so return values need not be explained, but a describe tool with two undocumented required params and no statement of what is described (structure? indexes? samples?) leaves the agent guessing.
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?
Both required parameters (database, collection) have 0% schema description coverage, and the description adds no meaning to either – no format, no examples, no required-scoping explanation. With two undocumented params, the description fails to compensate for the coverage gap.
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 name says describe_collection, but the description claims the tool 'Inspects MongoDB indexes' – a narrower and potentially different purpose. An agent comparing this against describe_table, list_collections, or list_schemas gets a conflicting signal about what is actually returned.
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 use this tool versus the many siblings (describe_table, list_collections, list_schemas, find_documents). The schema-flexibility remark is background trivia, not a usage condition or exclusion.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.