Create a Node-RED flow (tab)

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

Annotations declare readOnlyHint=false and openWorldHint=true, so mutation is already known. The description adds real value beyond them: the non-destructive scope ('leaving existing flows untouched'), the required env-flag prerequisites, and a safety comparison against the flow-replacing sibling.

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?

Four short sentences, each carrying distinct information: action, scope guarantee, object shape, and prerequisites/safety. The key differentiator against nodered_set_flows is front-loaded at the end of the first sentence and reinforced, with zero filler.

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?

For a mutating create with no output schema, it covers scope, prerequisites, and the alternative. The return value ('new tab id is returned') is only in the schema description and error behavior is unspecified, but annotations already carry the safety profile, so the gap is minor.

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 100%, so the schema already documents 'flow' and 'instance_id'. The description restates the 'label' and 'nodes' shape (the schema also mentions an optional 'configs'), adding no syntax detail beyond what structured data provides. Baseline 3 applies.

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?

Specific verb+resource: 'Add a new Node-RED flow (a new tab) with its nodes.' It also distinctly separates itself from the sibling nodered_set_flows by naming it directly, so an agent can route correctly without opening either schema.

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?

Explicitly states the alternative ('Safer than nodered_set_flows because it cannot disturb other tabs') and the prerequisite conditions (HA_ALLOW_WRITE=true and HA_ALLOW_CONFIG_WRITE=true). The when-to-use and the safer-vs-broader choice are both spelled out.

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