rca_graph_add_edge

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

The description discloses the key behavioral trait that edges causing cycles are automatically rejected, and states the return type (JSON confirmation or cycle-detection error). Annotations declare readOnlyHint=false and destructiveHint=false, so the description adds context about cycle prevention. However, it fails to mention behavior on duplicate edges (e.g., replace, error) or the required token field for authentication, leaving gaps in understanding side effects.

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 extremely concise: two sentences plus a compact Args/Returns block. Every sentence contributes meaningful information (operation, constraint, parameter summary, return type). No fluff, no redundancy. It is front-loaded with the core action. Ideal length for quick comprehension.

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 that the tool has a nested parameter object with many properties, the description covers the main goal and constraint but lacks details on required parameters like token and optional ones like method. The output schema exists (though not shown), and the description states the return format partially. Missing clarity on authentication (token) and edge conflict resolution makes it moderately complete at best.

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?

The schema has 0% description coverage, so the description must compensate. It lists the main parameters (graph_id, source, target, weight, confidence, method) and provides value ranges for weight and confidence [0,1]. However, it omits the required token parameter entirely and does not explain the meaning of method or client_id. The description adds some semantics but not enough for full understanding of all 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 clearly states the tool's purpose: 'Add a directed causal edge (source → target) to a graph.' It specifies the verb 'Add', the resource 'causal edge', the direction, and key constraint (DAG enforcement). This cleanly distinguishes it from sibling tools like rca_graph_add_node (adds nodes) and rca_graph_remove_edge (removes edges).

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 no explicit guidance on when to use this tool versus alternatives, nor does it mention prerequisites or when not to use it. While the DAG enforcement hint suggests it's for acyclic graphs, there is no comparative advice like 'use rca_graph_add_node to add nodes' or 'use rca_graph_remove_edge to remove edges'. This forces the agent to infer usage from the name alone.

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