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 output fields (budget, spend, expiry, status) but does not mention that this is a read-only operation, any authentication requirements, or potential error states. The description gives some behavioral insight but not complete transparency.

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?

A single, front-loaded sentence that states the core action and resource first, then lists the returned attributes. No filler or redundancy; every word contributes to the tool's purpose.

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?

Given there is no output schema, the description adequately explains return values (budget, spend, expiry, status). It also clarifies the scope ('delegated by the current agent'). Missing pagination or error handling details are minor for a list tool of this complexity, and the parameter is covered by the schema.

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%, so the optional 'key' parameter is already documented. The description does not add any meaning about the parameter beyond what the schema provides, and the tool's purpose (listing subagents) implies the key is rarely needed when auth is present. Baseline 3 is appropriate since schema handles the parameter semantics.

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 states a specific action ('List') on a clear resource ('child keys delegated by the current agent') and enumerates the returned data (budget, spend, expiry, status). This distinguishes it from siblings like mint_subagent or revoke_subagent, which manage subagents rather than list them.

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 implies usage for viewing subagents, but does not explicitly state when to use it over alternatives or mention exclusions. No guidance is given on when to prefer this tool vs. spend or revoke_subagent, though the sibling context makes the read-only nature obvious.

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