upgrade_unit

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 that upgrading consumes movement and requires specific conditions, but lacks details on failure modes or additional effects beyond movement consumption.

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 succinct: one sentence for purpose, then clear bullet-point-like style for arguments and requirements. No unnecessary words, earning its place.

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 the tool has one parameter, no annotations, and an output schema (not detailed but exists), the description covers key aspects (purpose, prerequisites, side effects). It omits return value details, but the output schema compensates.

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?

The only parameter, unit_id, is described as 'The unit's composite ID (from get_units output)', providing crucial context beyond the schema's type integer. This helps the agent understand where to obtain the value, though a format example would be helpful.

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 the action ('Upgrade a unit to its next type') with an example ('Slinger -> Archer'), distinguishing it from sibling tools like promote_unit which have different functions.

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 specifies prerequisites (right technology, enough gold, moves remaining) and side effects (movement consumed), guiding the agent on when to use the tool. However, it does not explicitly mention when not to use or provide alternatives.

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