Add/remove DNR users

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

Beyond the annotations (readOnlyHint=false indicating mutation), the description discloses that raw emails are SHA-256 hashed automatically and that the hashed flag should be true if emails are already hex SHA-256. It also specifies that expires_at is optional ISO 8601 and must be under 13 months. These are valuable behavioral details not in the schema or annotations.

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 a compact two sentences that front-load the primary purpose, then deliver essential constraints (hashing, expiry). Every phrase earns its place with no redundancy or 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?

The description covers core operation and key behavioral rules but omits prerequisites like the existence of the DNR list or how to obtain its ID (e.g., via x_ads_list_dnr). It also does not mention response behavior or error conditions, though the absence of an output schema lowers the expectation for return details. Overall, adequate but with notable gaps for a mutation tool.

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?

With schema description coverage at only 17%, the description compensates well. It clarifies that emails are the only accepted input type, explains the hashed flag and its condition, and defines the operation values (Update/Delete) through the opening phrase. It does not explicitly define do_not_reach_list_id, but that parameter's purpose is evident from the name.

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 clearly states the tool adds (Update) or removes (Delete) emails on a Do Not Reach list, which is specific and actionable. It does not explicitly differentiate from sibling tools like x_ads_create_dnr or x_ads_delete_dnr, but the phrase 'on the Do Not Reach list' implies an existing list, making the purpose distinct enough.

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 implies usage (manage DNR users on an existing list) but does not explicitly state when to use this tool versus alternatives such as x_ads_create_dnr (create a list) or x_ads_delete_dnr (delete a list). No exclusions or alternative routing are provided, leaving the agent to infer.

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