list_devices

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

With no annotations, the description carries the full behavioral burden. It discloses useful context — early-access status, the three access models, and that pricing is 'indicative' — but says nothing about pagination, result freshness, auth requirements, or rate limits, so the agent still lacks operational details.

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?

It is a single well-packed sentence using semicolons to group device types, access models, pricing, and status. Nothing is wasted, though the fragment style and absence of an explicit verb make it slightly less immediately parseable.

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?

With no output schema and no parameters, the description must convey what comes back, and it does list the major result categories (device types, access models, pricing, wave status). However, it omits the workflow context (that this precedes reserve_device) and any result-shape or pagination detail, leaving a gap for an agent choosing among four siblings.

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 takes zero parameters, so there is nothing for the description to clarify; baseline 4 applies. The field names it lists correspond to result data rather than inputs, which is appropriate here.

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 enumerates exactly what the tool surfaces — a catalog of reservable devices (real iPhone, Pixel, Galaxy, mid-range Android, Simulator, Emulator) with access models and pricing — which clearly identifies it as the discovery/catalog tool. It lacks an explicit verb ('list') and doesn't differentiate itself from the sibling 'status', which the phrase 'current wave status' arguably overlaps with.

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 explicit when-to-use guidance, no mention of 'reserve_device' as the follow-up action, and no statement of when this tool should be preferred over 'ask' or 'status'. The agent can infer it is a pre-reservation browse step, but nothing in the text says so.

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