Retrieves the indexes of a MongoDB collection, including keys and options such as unique, sparse, TTL, and partial filters, to help inspect and manage query performance.
Indexes of a collection with keys and options (unique, sparse, TTL, partial filter).
| Name | Required | Description | Default |
|---|---|---|---|
| database | No | ||
| collection | Yes | ||
| connection | 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 readOnly/idempotent/non-destructive, so the safety bar is low, and the description still adds value by disclosing the shape of the returned data (keys plus index options like TTL and partial filters). It stops short of saying how database/connection defaults resolve, but the return-content disclosure is a genuine addition given there is no output schema.
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?
One compact sentence with the resource and the notable option types front-loaded; nothing is wasted. It is a fragment rather than a full sentence, but that costs no clarity here.
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 read-only listing tool the description covers purpose and return content adequately, and annotations cover safety. It is still incomplete on how database and connection selection work and offers no hint about the return container (list vs. map) in the absence of an output schema.
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% across three parameters, and the description only implicitly references 'collection'. The optional database and connection parameters and their default-null fallback behavior are unexplained in both schema and description, leaving real ambiguity about scope.
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 resource (indexes of a collection) and what it returns (keys and options such as unique, sparse, TTL, partial filter), which cleanly distinguishes it from create_index and drop_index siblings. The verb is only implied by the noun phrase, but the intent to enumerate is 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?
There is no statement of when to call this versus alternatives (create_index, drop_index, collection_stats) and no prerequisites or conditions. The agent must infer that this is a read-only inspection step before index changes.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.