Retrieve sections or blocks from any Slack canvas by supplying its canvas ID. Use this to read and process canvas content without manual browsing.
Look up sections/blocks in a canvas. Requires canvases:read scope.
| Name | Required | Description | Default |
|---|---|---|---|
| canvas_id | Yes | Canvas ID |
Changes observed during successful MCP inspections.
v0.1.8Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the burden of behavioral disclosure. It states the required auth scope ('Requires canvases:read scope') and implies a non-mutating read operation via 'look up', but does not disclose return structure, pagination, or error behavior.
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?
One concise sentence communicates the action, resource, and required scope with no filler. All content is relevant and front-loaded.
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 simple one-parameter lookup tool, the description plus schema provide adequate context to invoke it correctly. It could be slightly more complete by stating what the return value contains, but the lack of output schema and simple signature make the current definition mostly sufficient.
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 documents the only parameter canvas_id sufficiently for a baseline. The description adds no additional meaning about the parameter beyond what the schema already contains.
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?
States a specific verb ('look up') and resource ('sections/blocks in a canvas'), clearly distinguishing it from sibling tools like create_canvas, edit_canvas, and delete_canvas. The scope requirement reinforces the read-only nature.
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 verb 'look up' implies use when the agent needs to retrieve canvas sections, but there is no explicit guidance about when not to use it or which alternative to choose. The canvases:read scope is a useful prerequisite but does not provide direct comparison to sibling tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.