Renforge Measure

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

With no annotations present, the description carries the burden and does so fairly well: it says the tool works 'without eyes' (no screenshot), returns actionable deltas in logical pixels, adds a `pass` verdict only when `tolerance` is supplied, and that `contrast` samples the live frame live rather than from cached data. It does not state side effects, permissions, or whether the operation is purely read-only, which is the remaining gap for an unannotated tool.

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 purpose is front-loaded in the first clause, followed by parameter and return semantics in tight, backticked fragments. Every sentence carries distinct information — the action list, target resolution, return units, and the tolerance/contrast special cases — with no filler.

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 need minimal prose, and the description still usefully names the delta/tolerance-verdict shape. It also answers the key integration question (where node ids come from). The residual gaps are the unexplained `project_path` and the absence of any guidance relative to overlapping siblings.

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%, so the description must compensate and largely does: `action` is enumerated (7 values), `targets`/`within` are defined as either a `renforge_scene_tree` node id resolved live or a literal bounds object `{x,y,width,height}`, and `tolerance` is explained as a pass/fail threshold. Only `project_path` goes unexplained, but its meaning is largely self-evident.

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 and resource ('measure pixel relationships between scene nodes') and enumerates the seven measurement modes, so its scope is clear. However it never differentiates itself from sibling tools — notably `renforge_distribute`, which appears to overlap with this tool's `distribute` action — so the agent gets no sibling-level disambiguation.

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 per-action explanations imply when each mode applies (e.g. `contrast` samples the live frame for a WCAG ratio), which gives implied usage. But there is no explicit when-to-use, when-not, or pointer to alternatives (`renforge_get_ui_element_bounds`, `renforge_position_element`, `renforge_distribute` are all plausibly related), leaving the routing decision to inference.

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