Project Attribution Axis

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds real behavioral context beyond them: the projection carries axis content plus a two-hop Merkle path and enables root reconstruction without exposing the other three axes, which is genuinely useful for an agent reasoning about disclosure.

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 front-loaded sentences with no filler; the purpose and output shape come first. The trailing 'axis: D | P | G | C' repeats the schema enum and is mildly redundant, costing a point.

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?

For a read-only two-parameter tool with no output schema, the description does the important work of describing what the projection contains and what it enables downstream. It is essentially complete for invocation, with the only gap being the absence of guidance tying it into the surrounding APS attribution workflow.

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 100%, so the baseline is 3. The description restates the axis enum ('D' | 'P' | 'G' | 'C') but never decodes what D/P/G/C stand for or how the choice affects the output, and it adds nothing about the primitive parameter beyond the schema's reference to aps_construct_attribution_primitive.

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 — 'Extract a single-axis projection from an AttributionPrimitive' — and even explains the shape of the output (axis content plus a two-hop Merkle path). It is clearly distinguished from verification siblings like aps_verify_attribution_projection by being the extraction step, though it never names those siblings explicitly.

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 clause 'lets a downstream verifier reconstruct the signed root without seeing the other three axes' implies the reason to use this tool (limited-disclosure verification), so usage is inferable. However, it never states when to choose this over aps_construct_attribution_primitive, aps_verify_attribution_projection, or aps_verify_attribution_primitive, nor any prerequisite conditions.

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