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

Annotations already declare destructiveHint=true and idempotentHint=false, so the safety profile is covered. The description adds real value beyond that by naming exactly what is destroyed ('the old key and link stop working') and what the caller must do with the result ('Save the new ones'), which is not derivable from the annotations.

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?

Three short imperative sentences, zero filler, with the core effect ('get a new key for the same identity') front-loaded and the destructive consequence immediately after.

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, non-idempotent mutation with no output schema, the description covers the essential behavior: the effect on the old credential, the irreversibility implied by the warning, and that new credentials are returned. It stops short of stating auth requirements or whether the call can be undone.

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% and the single agent_key parameter is fully documented in the schema (pattern, provenance, and when it may be omitted). The description adds no parameter-level detail, so the baseline of 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 (rotate) and resource (key) plus the key constraint 'for the same identity', which implicitly separates it from enroll (which issues a first key). It is clear and actionable, though it does not explicitly name a sibling tool to contrast against.

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?

Usage is implied rather than stated: the agent can infer 'use this when you need a fresh key'. There is no explicit when-not guidance (e.g., don't call this to obtain a first key, use enroll) and no mention of how often it is safe to call.

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