# hash_keys

Get all field names from hash. Args: key: The name of the key Returns: List of field names or error message

Agent View of the PolicyLayer registry record for `hash_keys`. HTML page: https://policylayer.com/tools/aws/hash-keys

## Facts

- Tool: `hash_keys`
- Server: AWS (`@awslabs/mcp`) — https://policylayer.com/tools/aws.md
- Install: `npx -y @awslabs/mcp`
- Homepage: https://github.com/awslabs/mcp
- Risk category: Read (Low risk)
- Registry record: grade F, identity verified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "hash_keys",
    "arguments": {}
  }
}
```

## Why hash_keys is rated Low

This tool performs a read-only query operation that retrieves field names from a hash data structure. It has no side effects, does not modify data, and does not execute code or commands. The minimal blast radius from misuse would be exposure of field names, which is low-severity information disclosure. The high confidence reflects the clear read-only semantics in the description.

From the tool's own definition: "Tool description states 'Get all field names from hash' with return value 'List of field names or error message'. The operation retrieves metadata about a hash structure without modifying, deleting, or executing code."

## Use case

AI agents call hash_keys to retrieve information from AWS without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches AWS:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "hash_keys": {}
  }
}
```

## Other tools on AWS (299)

- `bulk_delete_by_criteria` — Destructive — https://policylayer.com/tools/aws/bulk-delete-by-criteria.md
- `cache_delete` — Destructive — https://policylayer.com/tools/aws/cache-delete.md
- `cache_delete_many` — Destructive — https://policylayer.com/tools/aws/cache-delete-many.md
- `cache_delete_multi` — Destructive — https://policylayer.com/tools/aws/cache-delete-multi.md
- `cache_flush_all` — Destructive — https://policylayer.com/tools/aws/cache-flush-all.md
- `delete` — Destructive — https://policylayer.com/tools/aws/delete.md
- `delete_access_key` — Destructive — https://policylayer.com/tools/aws/delete-access-key.md
- `delete_datastore` — Destructive — https://policylayer.com/tools/aws/delete-datastore.md
- `delete_group` — Destructive — https://policylayer.com/tools/aws/delete-group.md
- `delete_image_set` — Destructive — https://policylayer.com/tools/aws/delete-image-set.md
- `delete_instance_in_series` — Destructive — https://policylayer.com/tools/aws/delete-instance-in-series.md
- `delete_instance_in_study` — Destructive — https://policylayer.com/tools/aws/delete-instance-in-study.md
- `delete_patient_studies` — Destructive — https://policylayer.com/tools/aws/delete-patient-studies.md
- `delete_resource` — Destructive — https://policylayer.com/tools/aws/delete-resource.md
- `delete_role_policy` — Destructive — https://policylayer.com/tools/aws/delete-role-policy.md
- `delete_series_by_uid` — Destructive — https://policylayer.com/tools/aws/delete-series-by-uid.md
- `delete_study` — Destructive — https://policylayer.com/tools/aws/delete-study.md
- `delete_user` — Destructive — https://policylayer.com/tools/aws/delete-user.md
- `delete_user_policy` — Destructive — https://policylayer.com/tools/aws/delete-user-policy.md
- `detach_user_policy` — Destructive — https://policylayer.com/tools/aws/detach-user-policy.md
- `json_arrtrim` — Destructive — https://policylayer.com/tools/aws/json-arrtrim.md
- `json_clear` — Destructive — https://policylayer.com/tools/aws/json-clear.md
- `json_del` — Destructive — https://policylayer.com/tools/aws/json-del.md
- `list_pop_left` — Destructive — https://policylayer.com/tools/aws/list-pop-left.md
- `list_trim` — Destructive — https://policylayer.com/tools/aws/list-trim.md
- `remove_instance_from_image_set` — Destructive — https://policylayer.com/tools/aws/remove-instance-from-image-set.md
- `remove_series_from_image_set` — Destructive — https://policylayer.com/tools/aws/remove-series-from-image-set.md
- `set_pop` — Destructive — https://policylayer.com/tools/aws/set-pop.md
- `sorted_set_remove_by_lex` — Destructive — https://policylayer.com/tools/aws/sorted-set-remove-by-lex.md
- `sorted_set_remove_by_score` — Destructive — https://policylayer.com/tools/aws/sorted-set-remove-by-score.md
- …and 269 more: https://policylayer.com/tools/aws.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=aws · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/aws