slack_post_ephemeral

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

Annotations already carry readOnlyHint=false, destructiveHint=true, idempotentHint=true, and openWorldHint=true; the description adds useful extra context that routing is scoped to the governed project/account connector, and that `effect` is agent-claimed but verified by Spring. It reasonably supports idempotent and destructive hints via the idempotency_key and write-approval fields, but still reveals nothing about the actual Slack-side delivery 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?

The description is compact and well structured: a short header identifying the operation, a one-line routing caution, then a scannable bullet list of parameters. No wordy boilerplate, and the routing restriction is placed prominently.

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?

Given there is an output schema and 7 parameters, the description reasonably covers the platform mechanics: routing authority, idempotency, effect declaration, and approval resume. The significant completeness gap is the opacity of the `arguments` payload and the lack of any behavioral statement tying the tool to a concrete Slack action, leaving an agent unable to construct a valid invocation without external Slack API knowledge.

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%, so the description carries the full burden, and it delivers: all seven parameters get a meaningful one-phrase definition, including project_id, project_ref, connector_account_ref, idempotency_key, effect, approval_ref, and arguments. The main residual gap is that `arguments` is explained as 'JSON string of arguments for the connector operation' without saying which keys (e.g. channel, user, text) post_ephemeral expects.

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 does say this is the Slack connector operation `post_ephemeral` with the platform tool id `slack.post_ephemeral`, so an agent knows it wraps Slack. However, it never states what post_ephemeral actually does (sending a message to a Slack user that only they can see), and it does not differentiate it from siblings like slack_post_message or slack_me_message — the burden is on the agent to already know Slack's API.

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 gives no guidance on when to choose this tool over sibling Slack tools such as `slack_post_message`, `slack_update_message`, or `slack_schedule_message`. The routing note ('Routes only through the exact project/account governed connector authority') is about authentication scope, not the operational selection criteria.

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