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

With only destructiveHint=true available, the description carries and delivers the behavioral burden: `channels` REPLACES the full selection, omissions are turned off, and null destroys the saved email address, Slack workspace, and temporary chat-setup marks — a precise statement of what gets destroyed. It also warns that saved choices may not deliver (Slack unconnected, email unsendable), that dot requires a separate verified notice_only subscription, and that dot may be ignored with a `notes` explanation.

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?

Front-loaded with the resource and scope, then layered semantics; every sentence (replacement rule, delivery caveat, null destruction, ChatGPT exception, exclusions) carries distinct information. The single dense paragraph is harder to scan than it needs to be for this many distinct rules, which keeps it just below top marks.

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?

There is no output schema, yet the description names the result fields an agent must consult (`delivering`, `notes`), which covers the return-value gap. For a destructive two-parameter write tool the coverage is strong, with the unresolved `slack_connection_id` semantics the main missing piece.

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 must compensate, and it does so thoroughly for `channels`: it explains each value (dot, email to your own account, Slack DM), replacement semantics, empty vs null, and conditional ignoring. `slack_connection_id` is never mentioned — no indication of when it is required or where the UUID comes from — leaving one of two parameters undocumented in both schema and description.

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 names the resource (shared-project and direct-chat notification settings scoped to yourself) and the operative behavior (saving the selected channels). The closing sentence explicitly excludes adjacent capabilities (subscribe, send test, reply, authorize work), which separates it from send_chat_notification_test and confirm_chat_notification_receipt. It stops short of naming a sibling or stating the verb as directly as an ideal definition would.

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 gives concrete usage conditions: save only explicitly selected channels, empty array turns everything off, null removes the saved preference, and dot is ignored for users receiving via a ChatGPT scheduled task. It also instructs the agent to read `delivering` before claiming delivery. It does not explicitly route to get_chat_notification_settings for the read case, so the when-not side is only implied.

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