mc_build

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

With no annotations, the description carries the full burden and does most of it: it discloses auto-navigation/pillaring, the default cap of 64, the ~10s time budget, partial-completion return fields (`used`/`held`, `remaining`, `hint`), and idempotent resumption. It does not say what happens if the inventory runs short or a cell is genuinely unreachable mid-fill, which is the main remaining gap for a world-mutating 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?

Well front-loaded: purpose, then use cases, then the time-budget warning and resumption rule. Every sentence carries information, though the emoji/bold formatting and the doubled explanation of 'just resend the same range' / 'already-correct cells are skipped' are slightly redundant.

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?

No output schema exists, and the description covers the important return signals (`used`/`held`, `remaining`, `hint`) plus the resumption loop, which is the behavior an agent most needs. What's missing is failure-mode coverage — running out of blocks, blocked pathing — for a tool with no annotations and 8 parameters.

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 coverage is only 25% — the six coordinate parameters carry no descriptions at all. The description partly compensates by establishing that the two triples are opposite corners of a solid cuboid and that `max` caps placement, but it never states the coordinate frame, whether corner order is interchangeable, or whether the y-bounds are inclusive.

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: fill the solid cuboid (x1,y1,z1)–(x2,y2,z2) with the named block, with a hard cap of `max`. It explicitly names the sibling it replaces for one-off placement (mc_act{place}), so an agent can choose between them without opening 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?

Gives concrete use cases ('a wall / a pillar / a platform') plus the alternative and when to prefer it. It also states the operational constraint (keep each call to ~10 seconds) and the exact recovery protocol: re-send the identical range, already-correct cells are skipped automatically rather than erroring.

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