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

Goes well beyond the annotations by explaining the ownership model: conventional names belong to one service per protocol, are recorded on first deploy, and never move by themselves — which is what makes this a destructiveHint=true action. It also discloses that nothing is deployed immediately and states the required permissions (applications.deploy, clusters.operate). It stops short of spelling out what is destroyed for the previous holder when the choice changes.

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?

Front-loaded with the core action, then the ownership model, then the failure mode, then the call modes, then permissions — a sensible ordering. The parenthetical list of protocol-to-variable mappings is longer than needed and mildly bloats an otherwise dense paragraph.

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?

No output schema exists, and the description does the needed work: it says nothing is deployed, that the next deploy applies the choice, and where to look when the state is broken. Only the exact effect on the previously-holding service is left implicit.

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 every parameter already carries a description, so the description's restatement of the instance_id/none=true alternation adds little new. Its enumerations (protocol examples) and the note that the instance must serve this environment over this protocol largely duplicate schema text, so 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 and resource: choose which managed service supplies a protocol's conventional connection names (DATABASE_URL, PG*, REDIS_URL, etc.) for one application environment, or that none does. This is clearly distinguishable from siblings like get_service_instance (diagnostic read) or prepare_service_retirement, and the naming examples make the target concept concrete.

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?

Explains the trigger condition explicitly ('When that service is retired while another service of the protocol still serves the environment, the application's deploys are refused until this is chosen') and names the two call modes (instance_id vs none=true). It also points at get_service_instance's connection_delivery.holder_gone as the diagnostic signal, though it never explicitly says when NOT to use this in favor of another tool.

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