yoto_list_devices

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that it returns 'names and status' and explicitly states it does not control or modify devices, which is consistent with the annotations. However, it does not disclose details like whether authentication is required or what 'status' includes, so it provides only modest additional behavioral context beyond the annotations.

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 a single concise sentence with the primary purpose front-loaded ('Read linked Yoto player names and status') and a clarifying negative statement following. Every word earns its place, and the structure makes the tool's intent immediately scannable.

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?

This is a simple, zero-parameter, read-only tool with annotations covering its safety profile. The description specifies exactly what is returned (player names and status) and limits scope to linked devices. No output schema exists, but for a list operation of this simplicity, the description provides sufficient information for an agent to invoke it correctly.

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 tool has zero parameters, and schema description coverage is trivially 100%. The description correctly focuses on what the tool returns rather than parameter details. No parameter information is needed, so the baseline of 4 for 0-parameter tools applies.

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 uses a specific verb ('Read') and a clear resource ('linked Yoto player names and status'), making its purpose immediately obvious. The explicit negative clause 'Does not control or modify devices' further distinguishes it from any mutation tools and reinforces its read-only scope. It is clearly differentiated from siblings like yoto_list_cards and yoto_get_card by naming the resource type (devices).

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 provides clear context that this tool is for reading linked devices and retrieving their names and status, and it explicitly states that it does not control or modify devices. While it does not name alternative sibling tools or give explicit when-not-to-use conditions, the usage context is clear, and the negative clause serves as a partial exclusion.

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