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

Annotations already declare readOnlyHint=true, so the safety profile is covered and the bar is lower. The description adds the backing endpoint (GET /contact-groups) and the shape of the alerting data returned, which is useful context, but it says nothing about pagination behavior or rate limits.

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 tight sentences, front-loaded with the verb and resource, followed by the practical payoff (the ids). No filler and nothing repeated from the title.

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, so the description carries the burden of describing returns — and it does list the relevant fields of a contact group. Pagination specifics live in the schema, so the only gap is that it doesn't outline the overall response envelope.

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% — page (starts at 1) and limit (1-100, default 25) are both documented in the schema. The description adds no syntax or format detail beyond that, so the baseline 3 applies.

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+resource ('List contact groups') and then defines what a contact group actually contains — alerting email addresses, mobile numbers, integration ids and ping URL. No sibling covers contact groups, so there is nothing to confuse it with, and the agent knows exactly what comes back.

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 tells the agent what to do with the result: 'Use their ids in a check's contact_groups.' That is clear context and an actionable next step. It stops short of explicit when-not guidance (e.g. paging vs. searching), but no obvious alternative tool exists for this resource.

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