list_servicesIdentify which services appear in a specified time window and see which telemetry signals (metrics, logs, traces) have data for each, so you can scope investigations.
Services seen in the window and which signals (metrics, logs, traces) have data for each.
| Name | Required | Description | Default |
|---|---|---|---|
| since | No | Window start: RFC 3339 time or a duration ago. Default 30m. | |
| until | No | Window end. Default now. |
Changes observed during successful MCP inspections.
v0.2.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the meaningful behavioral detail that the result is window-scoped and reports which signals have data per service, but says nothing about pagination, empty results, or service identity semantics.
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?
A single tight sentence with no filler, and the scope qualifier ("in the window") is front-loaded. It is slightly terse to the point of being a fragment, but nothing is wasted.
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 two-optional-parameter read tool with no output schema, the description usefully characterizes the return value (services plus their per-signal data coverage), which is the main thing the agent needs to know. Only minor gaps remain around result size and service naming conventions.
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 both since/until are documented with formats and defaults in the schema itself. The description only echoes the window concept without adding format or interaction detail, so the schema does the heavy lifting and baseline 3 applies.
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 a specific resource (services) and scopes it to a time window, plus discloses the per-service signal breakdown (metrics, logs, traces). It reads as a noun phrase rather than an explicit verb, but the listing intent is unambiguous and clearly distinct from siblings like new_errors or trace_diff.
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 reach for this tool versus the siblings (new_errors, trace_diff, what_changed), nor any prerequisite or exclusion. The agent must infer that this is the inventory/discovery entry point rather than anything the description states.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.