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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety profile is covered. The description adds genuine context beyond that: 'for good' signals permanence and 'the runtime holding it can no longer make requests' explains the concrete consequence. It stops short of stating whether the credential can be reissued, which keeps it just under a 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 short sentences, zero waste, with the permanence and effect front-loaded and the alternative redirect placed second.

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 single-parameter destructive tool with full annotation coverage and no output schema, the description supplies everything an agent needs: the irreversible effect and the correct routing to the pausing alternative.

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 the single credential_id parameter is documented in the schema ('The credential's id, from get_agent'). The description adds no syntax or sourcing detail beyond what the schema already provides, 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 and resource ('Revoke one instance credential') and immediately clarifies the effect on the runtime holding it. It also explicitly distinguishes itself from update_agent_instance, which pauses rather than revokes.

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?

Names the alternative use case and the exact tool to reach for it ('To pause an instance instead, disable it with update_agent_instance'). This is explicit when-to-use-this vs when-to-use-an-alternative guidance.

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