Fetch service-level Prometheus metrics for SLI/SLO analysis, including error rates, latency spikes, CPU, and memory over a configurable time window.
Fetches Prometheus metrics for SLI/SLO analysis, specifically error rates and latency spikes.
| Name | Required | Description | Default |
|---|---|---|---|
| service | Yes | The service name to query metrics for | |
| metricType | Yes | The type of metric to fetch | |
| timeWindowMinutes | No | Time window in minutes (default: 30) |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the full behavioral burden. It implies a read-only fetch but does not disclose auth requirements, rate limits, return format, or side effects. This minimal disclosure is a 2.
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 sentence, front-loaded with the action and resource. The trailing 'specifically' clause is slightly misleading given the broader enum, but otherwise there is no waste. A 4 reflects the minor inaccuracy.
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 read-only metrics fetch with no annotations and no output schema, the description should clarify output shape or usage boundaries. It covers purpose and metric types but omits behavioral and output details. A 3 is appropriate given the tool's simplicity and complete parameter 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 coverage is 100%, so all three parameters are documented in the schema. The description adds no syntax, format, or default information beyond what the schema provides, and its 'specifically' clause conflicts slightly with the metricType enum. 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 states a specific verb (Fetches) and resource (Prometheus metrics), and adds the analysis context (SLI/SLO). It does not explicitly differentiate from sibling tools, so it falls short of a 5. The clause 'specifically error rates and latency spikes' slightly undersells the cpu/memory enum values but the core purpose is clear.
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?
It gives a clear context ('for SLI/SLO analysis') but does not name alternatives or state when not to use it. No prerequisites or exclusions are provided. This is clear context without routing guidance, matching a 4.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.