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

No annotations are provided, so the description carries the full burden. It discloses the scoping behavior (budget, expiry, daily limit, allowlist) and that the child can spend only within these, plus revocability. However, it omits details like idempotency, failure modes, exact permission requirements beyond top-level, and what happens to existing keys. Given zero annotation coverage, a 3 is appropriate – it's not misleading but lacks depth.

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 three sentences, front-loading the core action and constraints. It has no wasted words, though it packs several ideas (scoping, permission, revocability) into a dense paragraph. Still very concise relative to the complexity.

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 tool with 7 parameters and no output schema, the description covers the main behavior and constraints but does not explain the return value. Since there is no output schema, agents may not know what to expect (e.g., the generated child key). It also doesn't mention error cases or how to use the returned key. This is a noticeable gap for a creation tool.

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 every parameter is already documented. The description adds minimal value by grouping key parameters ('budget, expiry, daily limit, and tool allowlist'), but it doesn't introduce new meaning or clarify relationships beyond the schema. Baseline 3 is correct when the schema does the heavy lifting.

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 uses a specific verb ('Delegate a scoped child key') and a clear resource ('a worker'), and it distinguishes itself from sibling tools like revoke_subagent and list_subagents by focusing on creation with scoping constraints. It is immediately evident what the tool does.

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 gives a clear usage condition: 'Only top-level agents can delegate.' It also implies the lifecycle (revocable any time) and scoping constraints. However, it does not explicitly name alternative tools or state when NOT to use it, but the condition is strong enough to guide the agent.

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