mcp_gpio_scan

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

With no annotations, the description carries the burden and does well: it discloses the returned fields and exactly which pins are included or excluded on Raspberry Pi, Pico, and ESP32. It stops short of explicitly stating read-only/no-side-effect behavior or permission requirements, but the scan semantics strongly imply a read operation.

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?

A single well-structured sentence front-loads the action and then adds necessary platform-specific scope. Every clause earns its place by clarifying what is scanned or what is returned.

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?

Because there is no output schema, the description appropriately lists the return fields (value, type, pull resistor, name) and platform coverage. The main remaining gap is the undefined `agent` parameter semantics, which matters for correct invocation.

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 sole required parameter is `agent`, but the schema provides 0% description coverage and the description only says 'on `agent`'. It does not explain what an agent identifier is, its expected format, or how to obtain one, leaving the only parameter under-specified.

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 states a specific verb ('Scan') and resource ('all hardware GPIO pins on `agent`') and enumerates the returned fields. It also gives platform-specific pin coverage, making it clearly distinguishable from single-pin siblings like mcp_gpio_read.

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 broad-scan framing implies this is for inventory/discovery rather than reading one pin, but it never explicitly says when to use it instead of mcp_gpio_read or mcp_gpio_watched. The usage is inferable but not guided.

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