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

Annotations already establish the safe read-only profile, and the description adds meaningful behavioral context beyond them: responses are JSON, results are scoped to the authenticated customer, `sources: null` means all sources including future ones, and the two ID fields have different routing purposes.

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?

It is front-loaded with the core action and return format, then moves into the high-value ID-routing distinctions. Every sentence contributes concrete information, and there is no 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 and an empty input schema, the description carries the full burden and does so well: it explains what is returned, the key fields, which identifier feeds which downstream tool, and the meaning of null `sources`.

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?

This tool has zero input parameters, so there is no parameter semantics to add and the schema baseline of 4 applies. The description instead adds useful return-field semantics for `id`, `channelId`, and `sources`.

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 and resource: list the authenticated customer's registered Slack/email notification channels. It also distinguishes the returned `id` from `channelId`, which is the main source of confusion for sibling tools that consume these channels.

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 provides clear downstream usage context by naming `save_alert_rule`/`set_alert_rule_delivery` and `set_issue_digest_config` and specifying which identifier each expects. It does not explicitly state when not to use this tool or name a direct alternative, so it stops short of the top score.

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