slack_unread

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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds genuinely useful behavior beyond that: it is capped at 20 conversations, it is backed by conversations.info plus conversations.history, and count stops at limit with has_more signaling truncation. Only the per-channel return shape is left unstated, and an output schema exists.

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 with the core purpose front-loaded and the API caveat placed where it matters. The parenthetical API call list is slightly noisy but short enough to earn its place.

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?

With annotations covering the safety profile and an output schema covering return values, the remaining burden is small. The one real gap is the undocumented workspace parameter, which leaves an agent guessing at required input semantics.

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 0%, so the description must carry parameter meaning. It does explain channel_ids indirectly via 'up to 20 channels/DMs' and explains limit's truncation semantics, but the required workspace parameter is never mentioned and the 20-conversation cap is not tied explicitly to the array.

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 gives a specific verb and resource: it counts messages that arrived after the read marker per channel/DM, which separates it from slack_read_channel and slack_search. It never names a sibling explicitly, so the differentiation is left to inference, but the purpose itself is unambiguous.

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?

It communicates a real usage constraint: there is no full unread inbox like the app, so the caller must name channels. That implies when the tool is appropriate, but it never states when to prefer slack_read_channel or slack_search instead, or what to do when the channel set is unknown.

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