Loki MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description claims 'List values' which implies a read-only operation, but annotations declare readOnlyHint=false and destructiveHint=true. This is a direct contradiction that could lead to catastrophic misuse by an agent believing this is a safe query when it actually performs destructive operations.

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?

Single sentence is appropriately brief, but given the destructive annotations and operational complexity, the description is under-sized rather than elegantly concise. Critical safety information is omitted, making the brevity inappropriate.

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?

Despite having destructive annotations and three parameters (including time ranges), the description provides no output schema hints, no explanation of the destructive nature, and no guidance on the Loki query patterns. The contradiction with annotations further erodes completeness.

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?

With 100% schema description coverage, the structured documentation carries the full parameter semantics. The description mentions 'specific label name' which aligns with the required 'label' parameter, but adds no format details, validation rules, or time range behavior 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 provides a clear verb ('List') and resource ('values for a specific label name in Loki'), specifying the domain. However, it does not explicitly differentiate from sibling tool 'labels' (which likely lists label names rather than values), which could cause selection ambiguity.

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?

No guidance provided on when to use this tool versus alternatives like 'query' or 'labels'. No mention of prerequisites such as requiring the label name to exist, or when the time range parameters are necessary versus optional.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.