change_color

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It does well: it tells the agent that the operation is a mutation (changing a color), that a conflict can be detected by the mentioned error, and that the API may return a 409 status if the new color conflicts with a neighbor. This is actionable behavioral detail beyond the schema.

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, zero fluff. The purpose is stated first, then the trigger condition, then the parameter guidance and a note on conflict behavior. Front-loaded and efficient.

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 simple mutation with two parameters and no output schema, the description covers the essential context: why to call it, what precondition to check (get_colors), and what error to expect. The only omitted detail is whether the change is immediate or reversible, but that is minor given the low complexity and clear guidance.

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%, so the description doesn't need to repeat parameter meanings beyond what the schema already describes. The description adds value by linking color_id to the get_colors palette and advising the agent to use the picked value, enriching the bare schema definition of 'Color index from the palette'. api_key is generically described in the schema, but that's acceptable given full 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 states a specific verb ('Change your kingdom color'), identifies the resource ('kingdom color'), and distinguishes it from siblings by referencing the 'color-conflict error' and the get_colors palette lookup. It clearly differentiates change_color from adjacent tools like get_colors and get_neighbors by specifying its purpose is to modify the color to resolve conflicts during claims/builds.

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 explicitly says when to use the tool: 'when a neighbor kingdom has the same or visually-similar color and your claim/build actions fail with a color-conflict error.' It also gives a clear directive to pass the color_id from get_colors, effectively naming the related tool to consult first. There is no exclusion statement, but the context is so specific that the agent knows the trigger condition and the prerequisite.

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