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

Annotations already declare readOnlyHint and destructiveHint=false, so safety is covered. The description goes further and, with no output schema, enumerates the returned fields (account, post or every post, keywords, DM text, public replies, on/off, stats) and what ruleId adds (commenter identity and sent/failed/skipped with failure reason).

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 front-loaded sentences with no filler; the concept definition comes first and the ruleId behavior second. It is dense but every clause carries information an agent needs.

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 read-only list tool with no output schema, the description adequately covers the return shape and the optional drill-down. Minor gap: no mention of pagination or result limits when listing many rules.

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 100%, so the baseline is 3. The description clarifies the effect of ruleId (adds latest activity) but adds no syntax or format detail for accountId or workspace beyond what the schema already states.

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 (List) and resource (Comment to DM automations), then defines the concept precisely: a keyword comment on an Instagram or Facebook Page post triggers an automatic DM. This clearly separates it from siblings like list_dm_automations and the create/update/delete_comment_dm_rule family.

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 explains the conditional drill-down (pass ruleId to also get latest activity), which is useful usage guidance. However, it never states when to prefer this over list_dm_automations or when not to use it, so routing between the two listing tools is left to inference.

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