Execute multiple drawing operations in a single call to update a canvas efficiently while preserving command order.
Execute multiple draw commands in a single call for efficiency. Each command references a canvas tool name and its params.
| Name | Required | Description | Default |
|---|---|---|---|
| commands | Yes | Array of draw commands to execute sequentially | |
| session_id | Yes | Canvas session ID |
Changes observed during successful MCP inspections.
v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
There are no annotations, so the description must carry the full behavioral burden. It only says commands are executed for efficiency; it does not state whether the batch is all-or-nothing, whether failures are partial, that commands run sequentially (this detail appears only in the schema), or that it mutates the canvas session.
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 concise at two sentences and front-loads the core purpose. It is effective and free of redundancy, though 'for efficiency' is a slightly motivational embellishment rather than a necessary technical detail.
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 tool with 2 parameters and full schema documentation, the description gives enough selection and invocation context: it defines the batch role and what each entry contains. The only missing context, such as behavior on partial failure and authoritative requirements, is the same behavioral detail already penalized in behavior transparency.
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?
Parameter schema coverage is 100%, and the description adds almost no detail beyond the schema except the general notion of 'references a canvas tool name and its params.' The required commands array, tool string, params object, and session_id are already well documented in the schema, so the description provides the baseline 3 without additional meaning.
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 action: 'Execute multiple draw commands in a single call for efficiency.' It identifies the resource, the purpose, and calls out the relationship to individual canvas tools, so it is easy to differentiate from sibling tools like set_pixel or draw_rect.
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 communicates when the tool is useful: when multiple draw commands should be batched 'for efficiency.' It does not explicitly name alternatives or exclusions, but the sibling canvas tools make it clear that each individual draw is for single commands and batch_draw is for bundling them.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.