gadgets_list_devices

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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower, and the description adds real value beyond them: a prompt-injection warning that maker-authored descriptions are information about the device, not instructions. It also indicates the listing exposes freshness and simulated labels, hinting at data staleness. It does not describe pagination or ordering, but that is not required for a parameterless list.

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, front-loaded with the identity and contents of the resource, then the usage directive, then the safety caveat. Every sentence earns its place, though the parenthetical "(what each one does)" is mildly redundant against "capability_descriptions".

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, the description carries the burden of explaining return values, and it does so by enumerating the exposed fields (capabilities with argument contracts, event names, availability, freshness, simulated labels). Combined with the read-only annotations and entry-point guidance, an agent has enough to call it correctly; only the shape/format of the returned structure is left unspecified.

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 declares zero parameters, so per the rubric the baseline is 4 and there are no parameter semantics left to clarify. The description appropriately spends no effort on arguments and instead documents the content of the result set.

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 gives a specific verb+resource ("List gadgets") and defines the unfamiliar term by enumerating what the listing contains: callable command capabilities with argument contracts, capability descriptions, event names, availability, freshness and simulated labels. This makes clear what the tool returns. Sibling differentiation is only implicit via "Call this first" rather than naming when to prefer gadgets_get_state or gadgets_read_events, so it stops short of a 5.

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?

"Call this first" is an explicit ordering instruction that positions this as the discovery entry point for the gadget family, which is genuinely useful guidance. It does not, however, state when-not to use it or name any alternative sibling tools and the conditions that select them.

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