List monitors on this Heartbeat instance with current status (new/up/late/down). Names and statuses are public by design — every monitor has a public status page. Pass your secret key to also include that monitor's private ping/fail URLs in the result.
| Name | Required | Description | Default |
|---|---|---|---|
| key | No | optional monitor key; adds the private ping_url/fail_url for that one monitor |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, so the description need not restate that. It adds useful context about the public nature of names/statuses and explains that the secret key is required to expose private URLs, which goes beyond the annotation. It does not describe the output structure, but that is not heavily required for a read-only list tool.
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 two sentences, front-loaded with the core purpose (list monitors and status), immediately followed by the public nature and the optional key behavior. There is no wasted wording, and every sentence contributes to a clear 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?
For a simple list tool with one optional parameter and a readOnlyHint annotation, the description is complete. It covers the primary output (statuses), the optional behavior (key for private URLs), and the public/private design. There is no output schema, but the description sufficiently conveys what the tool does. Pagination or rate limits are not mentioned, but they are not critical for a straightforward list operation here.
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?
The schema already describes the 'key' parameter at 100% coverage, so the baseline for parameter semantics is 3. The description reinforces the effect of the key (adding private ping/fail URLs) and clarifies the public/private distinction, adding value beyond the schema's basic description. It does not introduce new parameter details, but it does enrich the context.
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 clearly states the action (list) and the resource (monitors on this instance), and specifies the returned status values. It distinguishes itself from siblings like create_heartbeat or ping_heartbeat by its listing and status-reporting intent, and the optional key for private URLs adds scope clarity.
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 provides clear context: it lists all monitors, and optionally adds private URLs for a single monitor when a key is passed. It does not explicitly mention alternatives or when not to use it, but the scope is evident. It lacks an explicit comparison to get_status or other siblings, so it does not fully meet the 'explicit when-not' bar.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool maps to a distinct action: creating a monitor, checking one monitor's full state, listing monitors, signaling success, and recording failure. get_status and list_heartbeats are the closest pair, but their cardinality and detail level make them easy to tell apart.
All tool names use lowercase snake_case with a clear verb-first pattern: create, get, list, ping, record. The nouns are all meaningful in the heartbeat domain, and there is no mixing of camelCase or vague verbs like 'process' or 'run'.
Five tools is well-scoped for a focused dead-man switch service. Each tool covers a necessary part of the workflow without redundancy or bloat.
The core loop is covered: create a monitor, ping success, record failure, and inspect status. However, there is no update, delete, or disarm tool, so changing monitor configuration or retiring a job leaves an active monitor that will eventually go down and alert.