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

Annotations supply the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), and the description usefully adds the operational consequence that notifications resume immediately plus the auto-discovery default for the Alertmanager endpoint. It does not discuss authorization needs or what happens when expiring an already-ended silence, so it adds context beyond the annotations but not comprehensively.

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 sentences, front-loaded with the action and effect, followed by the id-source and the optional-override caveat. Every clause earns its place with no restatement of the tool name.

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?

For a mutation tool with no output schema, the description covers purpose, effect, id acquisition, and endpoint discovery. It omits error/auth behavior, which is a minor gap given the annotations already declare the safety profile.

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 all five parameters are already documented in the schema, including the defaults for namespace/service/port. The description's mention of auto-discovery slightly reinforces but does not materially extend the schema semantics, 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 (expire/end) applied to a specific resource (a silence in the cluster's Prometheus Alertmanager) and adds the user-visible effect (matching alerts resume notifying immediately). An agent can distinguish this from create_alertmanager_silence and list_alertmanager_silences without opening any 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?

Explicitly routes the agent to the id sources ('list_alertmanager_silences or the create_alertmanager_silence response') and clarifies when to supply the optional namespace/service/port overrides (only for non-standard installs, otherwise auto-discovered). It does not state when NOT to use the tool or failure conditions, so it stops short of a full when/when-not rubric.

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