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

Annotations already declare destructiveHint=true and idempotentHint=true, but the description goes well beyond them: it states the effect is deferred until the gateway's next configuration poll, and it spells out the destructive consequence (scopes the revision omits are retired and their credentials dropped). That credential-loss detail is exactly the context an agent needs before invoking a destructive mutation and is not available in structured fields.

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, zero filler. The purpose and its variants come first, then the timing and side-effect detail — a correct front-loading order for a destructive tool.

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 two-parameter mutation with no output schema, the description covers purpose, timing, and destruction. It does not describe what a successful call returns (e.g. the resulting revision state) or whether the operation can fail if the revision is already active, but nothing critical to correct invocation is missing.

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 coverage is 100% and both parameters already document their source (`list_gateway_server_revisions`, `list_gateway_servers`). The description adds no semantics about revision numbering, ordering, or what happens if the revision equals the current active one. Baseline 3 applies where the schema does the heavy lifting.

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?

Names a specific verb and resource ('Make an existing gateway server revision the active one') and immediately disambiguates it from siblings by naming the three real-world scenarios (rollback, draft activation, re-serving a deactivated server). An agent can distinguish this from `deactivate_gateway_server` and the other `activate_*_revision` tools 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?

The parenthetical enumerates concrete situations that call for this tool, which is stronger than most definitions. It stops short of explicit exclusions (e.g. 'to undo without changing anything served, use get_gateway_server_revision first' or when to prefer `deactivate_gateway_server`), so no true when-not guidance.

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