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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds substantial behavior beyond that: the exact stat set returned (started, completed, handed off, link clicks, failed) and the run-level outcomes including the 24-hour window closing and human handoff. It does not mention pagination or result limits.

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?

Two sentences, front-loaded with the core listing behavior before the automationId extension. The parenthetical enumerations are dense but each carries real information about trigger types and run outcomes rather than 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?

With no output schema, the description carries the return-value burden and does so well, covering both the automation summary fields and the detailed run fields. Minor gaps remain: no pagination/limit behavior and no statement about what happens for an unknown automationId.

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 nonetheless adds meaning by explaining that automationId is not a filter but a mode switch that also returns the latest runs, and by spelling out what those runs contain (who triggered, steps sent, choices tapped, clicks, how it ended).

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 (List) plus a precise resource (DM automations) and immediately defines what an automation is: flows of messages, waits, conditions and handoffs run in Instagram DMs and Messenger. It is clearly distinguishable from the create_/update_/delete_dm_automation siblings and from list_comment_dm_rules.

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 states the context in which these objects exist (keyword DMs, story mentions, story replies, ref links) and explicitly tells the agent that passing automationId switches the call into a run-listing mode. It does not name any alternative tool or state when-not to use this one, so it stops short of full routing guidance.

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