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

With no annotations, the description carries the full burden and does well: it discloses the one-time plc_ token and expiry, the per-op return values, the token's invalidation after close, and that it absorbs the deprecated position_lifecycle_begin/position_lifecycle_step names. It stops short of stating cost/payment mechanics or permission requirements for the purchase.

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 sentences, front-loaded with the purpose and branch model, then exclusions, then return values. Dense but nearly every clause carries information; the deprecated-name note is useful but slightly tacked on.

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 9-parameter, multi-branch tool with nested objects and no output schema, the description covers the return values per op and the token lifecycle well. The remaining gap is the undocumented secondary parameters (chain, family, params, receipt, transaction), which an agent would have to infer.

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 56%, and the description adds real meaning for 'op' (branch selection) and 'lifecycle_token' (one-time plc_ token from the purchase). However, several parameters — chain, family, params, receipt, transaction — get no explanation in either the description or the schema, leaving a meaningful gap.

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 verb and resource ('buy a 24h Position Lifecycle bundle and run the guard, receipt and close steps') and enumerates the four branch values of 'op'. It also explicitly distinguishes itself from the sibling trade_guard, so an agent can tell the two apart without opening either schema.

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?

It gives explicit when-not guidance: not for a single pre-trade guard (route to trade_guard op check_safety), not for unrelated positions, and not with a token after close. The alternative and the condition that selects it are both named.

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