mcp_gpio_scan

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

With no annotations, the description carries the full burden. It discloses the read-only nature implicitly via 'Scan...return', the exact return fields, and hardware gating, but never states side effects, permissions, or error behavior on unsupported hardware. Adequate but incomplete for a tool with zero structured behavioral hints.

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?

One front-loaded sentence delivers the action, the return fields, and the platform-specific pin scope, followed by a short eligibility constraint. Efficient and dense, though the pin-range enumeration is long enough to slightly dilute the core action.

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?

There is no output schema, so the description correctly enumerates return fields (value, type, pull resistor, name) and states hardware and pin-range scope. Only error/failure behavior on non-Pi/Pico targets is left unaddressed.

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% for the single required parameter, so the schema contributes nothing. The description compensates only partially by naming `agent` as the target of the scan, leaving its format (ID? hostname?) and valid values unspecified.

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?

States a specific verb ('Scan') and resource ('all hardware GPIO pins'), plus the exact payload returned (value, type, pull resistor, name). The word 'all' plus the enumerated pin ranges distinguishes it from the single-pin sibling mcp_gpio_read without needing to open either schema.

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 only guidance is a hardware eligibility constraint ('Only supported on Raspberry Pi / Pico hardware'), which is useful but is a precondition, not when-to-use-vs-alternative guidance. Nothing says when to pick this over mcp_gpio_read or mcp_gpio_watched for inspecting pins.

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