last_moves

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

With no annotations, the description carries the full burden of behavioral disclosure. It explicitly states the default behavior, the parameter constraint (n >= 1), and the edge case outcome (empty list when n <= 0). It also clarifies the UCI format. This provides useful behavioral context beyond a simple operation, though it does not cover aspects like ordering or handling of insufficient history.

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 brief and front-loaded with the core purpose. The parameter section is clearly separated and adds necessary detail. It is appropriately sized for a simple tool, though it could be slightly more compact by integrating the default mention.

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's simplicity and the presence of an output schema, the description covers the essential behavior and parameter semantics. However, it misses usage guidance and sibling differentiation, particularly the distinction between last_moves and last_moves_detailed. This gap reduces completeness for an agent deciding which tool to invoke.

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 schema only provides the type and default for the n parameter. The description adds crucial semantics by specifying the minimum value (>= 1) and the exact behavior for invalid input (empty list), which is not present in the schema. This fully compensates for the 0% schema description coverage.

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 tool returns the last N moves in UCI format, with a default of 1. This identifies a specific verb and resource. However, it does not explicitly distinguish itself from sibling tools like last_moves_detailed, though the format mention provides some implicit distinction.

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?

There is no guidance on when to use this tool versus alternatives such as list_moves or last_moves_detailed. The description only explains what the tool does and parameter behavior, leaving the agent to infer usage context.

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