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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds the scoping to 'current customer' and notes it returns non-secret config (implying secrets are excluded) and includes a dashboardUrl, which is behaviorally relevant. It doesn't mention pagination or sorting, but for a zero-parameter tool with annotations covering safety, this is adequate.

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?

Three sentences, each carrying weight: the first lists the returned fields, the second explains the significance of slugs, and the third adds a pointer to where channels are managed. It's front-loaded with the core listing behavior and provides essential context without fluff.

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 the tool's simplicity (no params, no output schema, but a specific purpose within a larger platform), the description covers the essential information: what is returned, how to use the result (slugs for escalation rules), and where management happens. It doesn't describe the exact format of the config object or pagination, but for a list tool this is usually minor. Lacking an output schema, the field list is quite helpful.

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?

The tool has zero parameters, and schema description coverage is 100% (trivially, since there are no params). The description compensates by detailing exactly what will be returned for each channel, which helps the agent understand the output without needing an output schema. This exceeds the baseline 3 because it adds specific field names and their meaning (e.g., slugs referenced by escalation rules).

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 clear verb ('List') and resource ('notification channels'), and enumerates the returned fields (slug, name, type, config, enabled flag). It also distinguishes itself from the sibling get_channel by indicating it lists all channels for the customer, whereas get_channel likely fetches one. The mention of slugs being referenced by escalation rules adds useful domain context.

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 implicitly states when to use this tool: when you need to enumerate channels or find slugs for escalation rules. It doesn't explicitly or directly reference sibling list_channel_deliveries or get_channel, but the field list and the reference to escalation rules make the use case clear. No exclusions or alternative routing are stated, which is a minor gap.

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