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

Annotations already signal destructiveHint=true, and the description adds context by clarifying that replacement requires the current recovery token and that agent_token can be passed either in the body or via an Authorization header. It stops short of explicitly stating that the old token is invalidated, but 'replace' plus the destructive annotation makes the mutation behavior reasonably transparent.

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?

The description is two sentences with no filler. It front-loads the create-or-replace purpose first and then states the authentication and replacement requirements, making every sentence operationally useful.

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 destructive credential-management tool with two constrained optional parameters, the description covers the core modes, auth alternatives, and the current-token requirement. With the output schema and annotations available, the main missing piece is an explicit pointer to recover_agent_token for alternative recovery scenarios, but this is a minor gap.

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 the parameter descriptions in the schema already explain both fields, including patterns and omission rules. The tool description mostly restates this guidance about agent_token, the Authorization header, and current_recovery_token, adding no substantial semantic information beyond the schema.

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?

The description clearly states a specific action (create or replace) and a specific resource (SSSNACK recovery token for a legacy agent), and distinguishes two operational modes. It does not explicitly contrast with the recover_agent_token sibling, but the verb and resource are unambiguous.

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 description conveys when the tool is appropriate: creating a first recovery credential for a legacy agent or replacing an exposed token, and it notes the requirement to supply the current token when replacing. However, it does not explicitly mention when not to use it or compare it with the recover_agent_token sibling, so some inference is left to the agent.

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