rent_energy

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

The description reveals behavior beyond annotations: automatic TRX calculation, pre-checks, and differentiation between new and renewal behavior. Annotations indicate destructiveHint=true and readOnlyHint=false, which are consistent. The description adds valuable context without contradiction.

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 a single paragraph but flows logically: action, then new/renewal rules, then pre-checks. It is concise with no filler. However, breaking into bullet points could improve readability, but not required.

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?

The description covers inputs and behavior well but does not mention output or return format. Since there is no output schema, the agent must infer what the tool returns (e.g., transaction result). This is a gap for a tool that modifies state.

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%, but the description adds significant meaning: explains energyAmount minimums based on rental type, and clarifies durationHours conditional behavior. This goes beyond the schema's static descriptions, providing actionable semantics for the AI agent.

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 'Rent energy from JustLend for a specified receiver address.' It specifies the verb (rent), resource (energy), and platform (JustLend). It also distinguishes between new rentals and renewals, adding specificity. While it does not directly compare to siblings, the purpose is 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 provides explicit guidelines: durationHours is required for new rentals, optional for renewals; minimum energy amounts differ (300,000 new, 50,000 renewal). It mentions pre-checks (not paused, within limits, sufficient TRX). However, it does not state when not to use the tool or suggest alternatives, which would elevate it to a 5.

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