board_from_position_key

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

No annotations are provided, so the description is the sole source of behavioral info. It discloses the return structure (2x25 board array, position ID, key) and the input type, which covers the essential behaviour of this conversion tool. However, it doesn't mention error handling or validation of the key.

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 concise and structured with 'Args' and 'Returns' sections. The main sentence is clear, but the Args section is somewhat redundant with the schema and main text, though it adds a minor clarification.

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 that an output schema exists, the description appropriately focuses on the conversion logic and output fields. It sufficiently covers the tool's purpose and return values, but omits any error conditions, which are not critical for a simple converter.

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 has one parameter with no description coverage, so the description must compensate. The 'Args' section merely restates 'A GNUBG position key string,' adding little beyond the parameter name. It doesn't provide format examples or constraints.

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 'Convert a GNUBG position key string to a board representation,' identifying the specific input and output. This distinguishes it from the sibling 'board_from_position_id' which uses a different input format.

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 does not explicitly mention when to use this tool over alternatives, but the conversion from a key is implied. It lacks explicit guidance on when not to use it or which sibling to choose for other input types.

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