List keys and metadata by prefix in JayDB or JayDB Cloud. Set namespace and limit to narrow results.
List keys and metadata by prefix in JayDB or JayDB Cloud
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Max items to return (default: 50) | |
| prefix | No | Key prefix to list, e.g. "users/" or "boards/" | |
| namespace | No | Namespace name (defaults to JAYDB_NAMESPACE or "default") |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It does disclose the core read-only behavior and the fact that metadata is returned, but it does not mention pagination, ordering, or what happens when a prefix matches a large number of keys. This is adequate but leaves some behavioral gaps.
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?
The description is a single, front-loaded sentence with no filler. It immediately states the verb, resource, and scope, and every word contributes to the agent's understanding.
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?
Given no output schema and no annotations, the description should carry more contextual weight. It names the return concept ('keys and metadata') but does not explain the response shape, pagination behavior, or additional omitted details. It is sufficient for a simple list tool, but not fully complete.
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 100%, and all three parameters have meaningful descriptions in the schema. The tool description adds only the 'by prefix' notion, which reinforces the prefix parameter but does not add substantive semantic value beyond the schema.
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 uses a specific verb ('List') and names the resource ('keys and metadata by prefix') in JayDB or JayDB Cloud. The plural 'keys' and prefix scoping implicitly distinguish it from siblings like jaydb_get, jaydb_put, and jaydb_delete, so an agent can identify this as the enumeration tool.
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 states what the tool does but gives no explicit guidance on when to choose it over alternatives such as jaydb_get or jaydb_health. There are no usage conditions, exclusions, or comparative hints, so the agent must infer when listing is appropriate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.