Loki MCP Server

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

The description discloses the external system (Loki) and query language (LogQL), adding context beyond annotations. However, it does not explain the implications of destructiveHint=true or idempotentHint=false, nor does it describe the return payload or query cost characteristics.

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 single sentence is tightly constructed with no wasted words, front-loading the action ("Execute") and clearly stating the domain-specific operation type ("instant query").

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?

Given the complete input schema (100% coverage), present annotations covering safety hints, and simple parameter structure, the description is nearly complete. A minor gap exists regarding the output format (absent output schema), though 'query' implies data retrieval.

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?

While the schema has 100% coverage, the description adds valuable domain context: "LogQL" clarifies the query parameter's syntax, and "point-in-time" clarifies the time parameter's purpose. This exceeds the baseline expectation for well-schemed parameters.

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 specific verb ("Execute"), resource ("LogQL instant query"), and target system ("Loki"). The phrase "point-in-time evaluation" effectively distinguishes it from the sibling tool "query_range" (which implies a time range), making the scope 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?

The terms "instant query" and "point-in-time evaluation" implicitly suggest when to use this tool (single timestamp evaluation) versus the "query_range" sibling, but it does not explicitly name alternatives or state when-not to use it.

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