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

With no annotations, the description carries the full burden and does disclose the most important behavioral trait: it performs no signing and no broadcast, leaving those client-side. It also names both outputs. It stops short of stating determinism, error/validation behavior, or that it has no side effects at all.

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?

Two tightly packed sentences, front-loaded with the resource and output, then the signing boundary. No filler or repetition.

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 usefully states the two return artifacts, partially covering the absence of an output schema, and flags the non-signing scope. But for a 10-parameter tool with a nested metadata object and no annotations, it omits requiredness, defaults, and any parameter guidance, leaving real gaps.

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 only 30% across 10 parameters (including a nested metadata object), so the description is expected to compensate but adds zero parameter-level detail. It mentions none of lat/lng/name/owner_pubkey semantics, formats, or defaults, leaving most params documented only by their type/pattern.

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 (Build) and concrete artifacts: a canonical Locus mint payload and the exact OP_RETURN output script hex. This distinguishes it from sibling build_place_payload by naming the payload type, though it never explicitly contrasts the two.

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 'NO signing — assembly/sign/broadcast stays client-side' note implies this is a pure assembly step in a larger flow, which is useful context. However, it gives no explicit when-to-use vs. when-not guidance and does not route the agent to build_place_payload or other siblings for different payload types.

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