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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is known. The description still adds real value by spelling out permanence ('for good') and the functional consequence for the runtime, which annotations cannot express. It stops short of saying what happens to the instance's other credentials or whether the revocation can be undone, so not a full 5.

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, both load-bearing: the first defines the effect, the second routes to the alternative behavior. The irreversible consequence is front-loaded and there is no filler.

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?

With rich annotations, a single fully documented parameter, and no output schema, the description covers what an agent needs to invoke it safely. A minor gap remains around the instance's post-revocation state and any required permissions, but nothing blocking.

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?

Only one parameter, and the schema description is 100% covered, including the hint to obtain the id from get_agent. The description adds no syntax or format detail beyond 'one instance credential', 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 (Revoke), a specific resource (one instance credential), and the concrete consequence (the runtime holding it can no longer make requests). It also names the sibling tool it is not (update_agent_instance), so an agent can distinguish it from instance-management operations without opening either 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 an explicit alternative and the condition that selects it: to pause rather than permanently revoke, use update_agent_instance to disable the instance. When-to-use and when-not-to-use are both covered, which is unusually complete for a single-parameter tool.

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