Visualize a DataFusion execution plan

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

Annotations already mark the tool as read-only, idempotent, and non-destructive. The description adds a crucial behavioral note—'Does not execute SQL'—which assures the agent that invoking this tool has no side effects beyond producing a visualization. This goes beyond the annotations and adds valuable context.

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 a single, well-structured sentence that front-loads the primary purpose and adds the critical 'Does not execute SQL' clause at the end. There is zero filler, making it efficient and easy to parse.

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 simplicity (2 parameters, no nested objects), the description covers the essential behavior and parameters. The output schema is present, so return values don't need description. The only minor gap is a lack of mention of potential errors or size limits, but these are secondary for a read-only conversion tool. Overall, it is sufficiently complete for an agent to use correctly.

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 0% schema description coverage, the description carries the burden of explaining parameters. It does this well: 'plan' is described as 'raw DataFusion physical plan or EXPLAIN / EXPLAIN ANALYZE output' and 'format' is implied by the output types ('.excalidraw' or '.png'). The description provides enough meaning for an agent to understand what to pass, even though it doesn't enumerate valid format values explicitly (the schema enumerates them).

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 a specific verb ('Convert') and resource ('raw DataFusion physical plan or EXPLAIN / EXPLAIN ANALYZE output') and specifies the output types ('editable Excalidraw scene or PNG image'). This is unambiguous and leaves no doubt about the tool's function, even without siblings to differentiate from.

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 provides clear context: it is used to visualize DataFusion plans into images. It also includes an explicit exclusion ('Does not execute SQL'), which tells the agent when not to use it (if SQL execution is needed). There are no sibling tools to compare, but the usage context is well-stated.

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