slack_cancel_scheduled

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

Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=true, so the risk profile is covered. The description adds genuinely useful context by naming the required scope (chat:write) and the API method, but says nothing about irreversibility, failure when the message already posted, or rate limiting.

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?

A single front-loaded sentence with no filler; the parenthetical method/scope hint is terse and useful. It is efficient, though the tightness comes partly from under-specification rather than disciplined editing.

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?

An output schema exists so return values need not be explained, but for a destructive, open-world mutation with 0% parameter documentation the description should say where the scheduled message ID comes from and what happens on failure. Those gaps leave the agent under-informed for a 3-required-parameter write operation.

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% across three required parameters, so the schema offers only bare titles. The description does not clarify any of them — e.g. whether workspace is a name or ID, or what format scheduled_message_id takes — so it fails to compensate for the coverage gap.

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 ('Cancel a scheduled message') and even names the underlying API method, which cleanly separates it from slack_delete_message (deletes an already-posted message) and slack_schedule_message. It does not explicitly call out those siblings, so it stops 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?

There is no when-to-use guidance: nothing tells the agent where scheduled_message_id comes from (presumably slack_list_scheduled), nor how this differs from simply deleting a message. Usage is only inferable from the tool name and the required ID parameter.

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