configure_bus_spi

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

No annotations are provided, so the description carries the full behavioral burden. It discloses several important constraints: 'miso/mosi may be OFF but not both', 'timeout_s must exceed max clock pulse width', 'ss only in CS mode', 'ss_polarity only in CS mode', and defaults for dbits/endian/mode. However, it omits mutation scope (does it reconfigure an existing bus or create one?), whether configuration is persistent, and side effects on active acquisition. Given no annotations, this is more than a bare-bones description but still incomplete on mutation semantics.

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?

Structured as a one-line purpose followed by a parameter block in a consistent 'name: meaning' format. Front-loads the action, then enumerates parameters. Slightly dense but every line earns its place given 13 undocumented parameters.

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 13 parameters, 0% schema coverage, no annotations, and an output schema present (so return values need not be explained), the description supplies the parameter details the schema lacks. It omits when-to-use versus other bus tools and behavioral scope of the mutation, but for a configuration tool this is close to complete.

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% – the schema provides only types and no text descriptions. The description fully compensates by defining every one of the 13 parameters: sclk/clk_slope/miso/mosi/polarity/dbits/endian/mode/timeout_s/ss/ss_polarity/display, with value ranges and defaults. This is exactly the case where the description must carry parameter semantics, and it does so exceptionally well.

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 opens with a specific verb+resource+setting: 'Set Bus <n> to SPI decoding and configure it'. The protocol is explicit (SPI) and the operation (set/configure) is clear. Among sibling configure_bus_* tools, the SPI variant is distinguishable by the protocol name in the tool name and description.

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 description implies this is the SPI-specific configuration tool, with sibling tools for other protocols (configure_bus_parallel, rs232, iic, can, etc.) named in the tool list. However, it does not explicitly state when to choose SPI config versus the generic configure_bus, nor does it give preconditions or exclusions. Usage is implied by the protocol name rather than spelled out.

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