Update an existing canvas edge's color, label, endpoint sides, and end connections by ID, using the canvas path to target the right file.
Update properties of an existing canvas edge by ID.
| Name | Required | Description | Default |
|---|---|---|---|
| color | No | ||
| label | No | ||
| to_end | No | ||
| edge_id | Yes | ||
| to_side | No | ||
| from_end | No | ||
| from_side | No | ||
| canvas_path | Yes |
Changes observed during successful MCP inspections.
v0.2.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare idempotentHint=true and destructiveHint=false, but the description adds no behavioral detail beyond the word 'update'. It does not disclose partial-update semantics (whether unset fields are left unchanged), error handling, or the impact of null parameters, so it fails to add meaningful context beyond structured data.
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, efficient sentence that front-loads the action and target. It has no filler, though one might argue it is too sparse for an 8-parameter tool; nevertheless, the brevity itself is clean and structured.
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 mutation tool with 8 parameters, 0% schema coverage, and no output schema, a one-sentence description is grossly inadequate. The agent is left without knowledge of which properties can be updated, how edge_id and canvas_path are formatted, or what happens when the edge does not exist, making correct invocation unlikely.
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 must explain the 8 parameters, but it mentions none of them. Even ambiguous parameters like to_end, from_end, to_side, and from_side are left entirely unexplained, providing zero semantic value to the agent.
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 states a clear verb+resource: 'Update properties of an existing canvas edge by ID.' It distinguishes from adding or removing edges by saying 'existing' and 'by ID', but it does not explicitly name sibling tools like add_canvas_edge or remove_canvas_edges, so it falls short of a 5.
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?
No guidance is given on when to use this tool versus alternatives such as add_canvas_edge or update_canvas_node. The description does not mention prerequisites, conditions, or exclusions, leaving the agent to infer usage from the tool name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.