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

Annotations already declare readOnlyHint=true, so safety is covered; the description adds real behavioral value by disclosing the dry-run nature ('Nothing is sent') and the diagnostic content of the response (matched/suppressed routes, reasons, fallback). It stops short of noting auth requirements or any limits, but the additive context is solid.

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 tightly written sentences, front-loaded with the core action, then the safety clarification and the usage cue. Every clause carries information and nothing is padding.

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, the description must explain the return value, and it does so thoroughly – listing the reported destinations, match/suppression reasons, and fallback status. Combined with the readOnly annotation and the scoping fields, an agent has everything needed to call and interpret it.

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 100%, so the schema already documents all 7 parameters in detail, making 3 the baseline. The description restates the constituent fields (kind, severity, optional cluster/source/application/reference) but omits alert_id and adds no format or constraint detail beyond the schema.

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 (dry-run/preview) and resource (organisation's notification routing) with unusual precision, enumerating exactly what it reports: destinations reached, routes matched or suppressed and why, and home-channel fallback. The 'Nothing is sent' clause implicitly distinguishes it from the sibling test_notification_route, so an agent can tell them apart.

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?

Gives a clear context: 'Use this to verify routing before and after changing routes.' That is an unambiguous when-to-use signal, but it never names alternatives such as test_notification_route or list_notification_routes, nor states exclusion conditions.

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