Read or set fold state

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

Annotations already declare it is not read-only, not idempotent, and non-destructive, so the safety profile is covered. The description adds a genuine behavioral fact ('Non-foldables return foldable false') about edge-case output. It does not disclose auth needs, reversibility of a state change, or rate limits, so it is useful but not rich.

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?

Two sentences, front-loaded with the read behavior before the write behavior, with little waste. The wording is slightly tangled but the structure is 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?

An output schema exists, so return values needn't be explained, and the annotations carry the safety profile. It also notes the non-foldable case. What is missing is clearer usage framing and any statement about what a state change affects, which for a mutation-capable tool leaves a modest gap.

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?

Coverage is 50%: 'serial' is documented in the schema (exact ADB serial from mobile_devices_list), and the description compensates for the undocumented 'state' param by giving valid value forms ('OPEN or CLOSED or a numeric identifier'). That is meaningful semantics beyond the bare schema for the undocumented parameter.

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 conveys that this reads fold postures and can set them, and the title reinforces 'Read or set fold state'. However the phrase 'List cmd device_state postures' is awkward and half-restates an underlying command rather than cleanly stating the resource, so the purpose is only adequately clear. It does not explicitly distinguish itself from siblings like mobile_orientation, but fold state is distinctive enough.

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?

It implies usage: call without state to list postures, pass state to switch. That conditional is useful but unstated in when/when-not terms, and no alternative tool is named for adjacent needs. Adequate minimum-viable guidance.

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