stl_support_diff_device

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

Annotations already indicate read-only, idempotent, and non-destructive behavior. The description adds important behavioral details: it is 'deliberately forgiving' about input shapes and 'reports what it assumed,' which goes beyond the annotations by explaining how it handles unexpected input.

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?

The description is mostly succinct but includes a slightly tangential statement, 'a support tool that rejects the user's paste over a key name has failed at its one job,' which adds flavor but not essential information. Two paragraphs are structured well.

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?

The description covers the tool's purpose, parameter semantics, and some behavior. It does not mention the output format or return value, but given the output schema exists (though not shown) and the tool's straightforward nature, the missing detail is a minor 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?

The schema provides no descriptions (0% coverage), but the tool description fully compensates by explaining both parameters: expected_json is 'a file path or inline JSON -- typically the output of stl_support_repro' and actual_json is 'a file path or inline JSON captured from the device.' This is clear and complete.

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 clearly states the tool's action: 'Diff what a device actually rendered against what it should have.' It specifies the resource (device rendering vs. expected) and even references stl_support_repro as the source of expected_json, fully distinguishing its role.

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 gives contextual hints (e.g., 'pasted out of a bug report' and expected from stl_support_repro) but does not explicitly differentiate from sibling diff tools like stl_diff_summary or stl_diff_stop_ids. When to use this tool over alternatives is implied rather than stated.

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