create_slack_canvas

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

No annotations are provided, so the description carries the full behavioral burden. It discloses the supported markdown constructs, which is useful, but says nothing about permissions/scopes required, rate limits, or what happens when the channel already has a canvas — a behavior the schema's title description hints at but the prose ignores.

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?

Three tight sentences, front-loaded with the action, then the routing guidance, then the content-format detail. No 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 no-annotation, no-output-schema creation tool the description covers purpose, routing, and input format adequately. It omits the pre-existing-canvas behavior and any indication of what the caller gets back (e.g., a canvas ID), which are the remaining meaningful gaps.

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 coverage is 100%, so the baseline is 3. The description adds real meaning for the markdown parameter by enumerating supported syntax (headings, lists, checkboxes, bold, code), going beyond the schema's terse 'canvas body, as markdown'.

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 and resource ('Create a Slack canvas in a channel from markdown') and implicitly separates itself from send_slack_message by framing the artifact as durable reference material rather than a scrolling message. An agent can tell exactly what this produces without opening the 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?

Gives clear when-to-use guidance ('reference material people will come back to — a checklist, a runbook, a spec') and an explicit when-not ('rather than a message that scrolls away'). It stops short of naming a sibling tool by name, but the contrast against messaging is unambiguous.

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