Set Currency

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

The annotations already indicate this is a non-read-only mutation, and the description simply restates that via 'set'. It does not disclose what happens when currency is null, whether the preference is persisted globally or per user, or whether an invalid or unset value resets the preference. With no output schema, the response behavior is also undisclosed.

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 four words, front-loaded, and free of filler. It is appropriately sized for a simple setter, though the brevity comes at the cost of missing behavioral and usage context.

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 mutation tool with one optional nullable parameter and no output schema, the description is too thin. It does not explain null semantics, the effect on existing preferences, or what a successful invocation returns. The enum supplies valid values, but an agent cannot fully predict the tool's behavior from this definition.

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 description coverage is 0% and the description adds no parameter-level detail beyond the word 'currency'. The enum in the schema provides valid values, but the description does not explain the meaning of the currency field, the null option, or how it is applied. The description fails to compensate for the missing property descriptions.

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 'Set currency preference' uses a specific verb and resource, clearly identifying this as a write operation on a currency preference. It is implicitly distinguished from the sibling getCurrency, though it does not specify whose preference is affected or any broader context.

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?

No guidance is given about when to use this tool, what conditions lead to it, or how it relates to getCurrency. There is no mention of using getCurrency to read the current preference, nor any prerequisites or side effects. The usage is only implied by the name and description.

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