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

Annotations only declare it is a non-read-only, non-idempotent, non-destructive operation; the description adds substantial context beyond that: the silence starts immediately and is backdated one minute so it never sits pending, the duration ceiling is 30d, and the response carries the silence id that must be relayed. It also explains Alertmanager auto-discovery and when to override with namespace/service/port.

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?

Dense but front-loaded: purpose first, then matcher rules, duration bounds, comment requirement, timing behavior, and service discovery. Every sentence carries operational information, though the paragraph is long and could be broken up for faster scanning.

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 return-value burden and does so by noting the response contains the silence id. Combined with matcher constraints, duration limits, and auto-discovery behavior, an agent has everything needed to invoke this 7-parameter mutation correctly.

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 baseline is 3, but the description adds matcher strategy (anchor on exact alertname, add cluster/namespace) and clarifies the comment is the operator-visible reason, giving the agent decision guidance beyond the field docs. It does not add syntax detail for duration beyond what the schema already lists.

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 and resource (create a silence in the cluster's Prometheus Alertmanager) plus the observable effect (matching alerts stop notifying via Slack/email until the silence ends). It also names the sibling used for the inverse operation (expire_alertmanager_silence), so an agent can separate it from list_alertmanager_silences and expire_alertmanager_silence without opening a schema.

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 explicit selection rules (anchor on an exact alertname matcher, add narrowing labels like cluster/namespace, at least one exact non-regex matcher required) and a clear when-not boundary ('longer suppressions need a human in Alertmanager/Grafana'). It also routes follow-up work to expire_alertmanager_silence, leaving little to inference.

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