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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, and the description adds meaningful behavioral context beyond that: truncation can occur for large domains, properties must not be inferred from truncated results, and ordered output is 'most-connected memories first.' It also fully discloses the JSON return fields, including truncated counts, which helps the agent understand and safely interpret results.

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?

Every sentence earns its place: purpose and exclusions, parameter behavior, return shape, rendering guidance, and truncation caveat. The description is longer than usual but densely packed with necessary information and well-ordered from high-level purpose to concrete invocation details.

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?

There is no output schema, yet the description enumerates the full JSON response shape (mermaid, node_count, edge_count, nodes_shown, nodes_total, edges_shown, edges_total, truncated, memories, connections). It also covers invocation modes, limits, truncation semantics, and client-specific rendering instructions. Nothing an agent needs to correctly select and invoke this tool is missing.

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%, so the description carries full responsibility for parameter meaning. It clearly explains all three parameters: memory_id views a single memory and its direct connections, domain views the full domain graph, and limit is capped at 100 with a default of 40. This adds substantive meaning beyond the bare schema types.

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 opens with a specific verb and resource: 'Generate a Mermaid.js flowchart for human visual inspection only.' It also explicitly distinguishes itself from audit(mode=orphans), making it clear this tool is for visualization rather than orphan detection or programmatic analysis. The title 'Visualise domain graph' reinforces the purpose without creating 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?

The description provides explicit when-to-use and when-not-to-use guidance, including a direct alternative: 'NOT for orphan detection or programmatic analysis — use audit(mode=orphans) to find isolated memories.' It also explains when to pass memory_id vs domain, the limit default and cap, and how to render output depending on client support for HTML widgets. This is unusually actionable usage guidance.

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