Lists collections and views in a MongoDB database, returning type and estimated document count plus optional regex name filtering.
Collections and views of a database with type and estimated document count. name_filter: regex on the name, e.g. "^order".
| Name | Required | Description | Default |
|---|---|---|---|
| database | No | ||
| connection | No | ||
| name_filter | No | ||
| include_counts | No |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds the useful detail that counts are 'estimated' and that results include views as well as collections, but says nothing about cost, permissions, or behavior when database/connection are omitted.
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 compact lines with the resource and return shape front-loaded and the filter example second; nothing is redundant. Brevity tips into under-specification rather than padding, but the structure itself is efficient.
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?
A four-parameter tool with no output schema and zero schema description coverage needs the description to carry more weight. As written, an agent cannot tell what happens when database is null, what include_counts=true costs, or how connection scoping works.
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 compensate for four parameters and only handles one — name_filter gets a concrete regex example. The database, connection, and include_counts parameters are left entirely to their titles, and the interaction between include_counts and the 'estimated document count' claim is not explained.
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 the specific resource (collections and views of a database) and the returned fields (type, estimated document count), which distinguishes it from siblings like list_databases and list_indexes. It lacks an explicit verb, relying on the tool name to supply 'list', but the resource and scope are unambiguous.
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?
No statement of when to use this tool versus list_databases, collection_stats, or infer_schema. The name_filter regex example is the only piece of operational guidance, and it addresses syntax rather than tool selection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.