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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the description doesn't need to re-establish that this is a write. It does add genuinely new behavioral context by disclosing that send history is deleted too and why that matters (a new rule could DM the same people again). It stops short of stating irreversibility or permission requirements outright.

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, zero waste, with the destructive scope front-loaded and the safer alternative placed second where it reads as a guardrail.

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 two fully documented required parameters, no output schema, and annotations covering the safety profile, the definition is nearly complete. The only remaining gap is an explicit statement that the deletion is permanent and cannot be undone.

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% and both parameters are documented in-schema with sourcing hints (list_comment_dm_rules, list_workspaces). The description adds no parameter meaning beyond that, so the baseline 3 applies.

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 ('Deletes an Instagram comment DM rule') and adds the consequential scope ('and its send history'), which lets an agent distinguish it from update_comment_dm_rule without opening either schema.

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?

Explicitly routes the agent away from this tool when the intent is only to pause: 'To stop one for now, use update_comment_dm_rule with enabled=false instead.' Both the alternative and the selecting condition are named.

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