Apache Airflow MCP Server

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering safety and idempotency. The description adds valuable context beyond annotations: it clarifies what information is returned ('host + metadata, never secrets') and documents error behavior ('Raises: ToolError with compact JSON payload'), which helps the agent understand failure modes.

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 well-structured with clear sections for purpose, parameters, returns, and error handling. Each sentence adds value, though the error details could be slightly more concise. It's appropriately sized for a single-parameter tool with output schema.

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 tool's low complexity (1 parameter), rich annotations (readOnly, idempotent, non-destructive), and existence of an output schema (which covers return values), the description is complete enough. It covers purpose, parameter example, return content summary, and error behavior, leaving no critical gaps.

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 0%, but the description provides the parameter 'instance' with an example ('e.g., "data-stg"'), adding meaning beyond the bare schema. However, it doesn't explain where to get instance keys or validate formats, leaving some gaps. With one parameter and partial documentation, a baseline 3 is appropriate.

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 specific action ('Describe a configured Airflow instance') and resource ('host + metadata, never secrets'), distinguishing it from siblings like 'airflow_list_instances' (which likely lists instances) and 'airflow_get_dag' (which focuses on DAGs). The phrase 'never secrets' adds important scope clarification.

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 implies usage context by specifying it describes 'a configured Airflow instance' and returns metadata, suggesting it's for retrieving instance details rather than operational actions. However, it doesn't explicitly state when to use it versus alternatives like 'airflow_list_instances' or provide exclusion criteria.

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