aps_check_projection_consistency

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

The description fully specifies the return values: {same_receipt: true} for success, and {same_receipt: false, reason: ...} with four enumerated reason codes for failure. Since no annotations are provided, this output disclosure carries the transparency burden, though it doesn't explicitly confirm read-only behavior or describe malformed input handling.

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 two sentences: the first states the purpose, the second precisely lists the output schema and reason enums. No filler, well-front-loaded, and every word earns its place.

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 provides the complete output contract (since no output schema exists), covering both success and all failure reasons. It is sufficient for an agent to invoke and interpret results, though it omits edge-case behavior like invalid projection inputs.

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?

With 100% schema description coverage (projection_a and projection_b each have brief descriptions), the baseline is 3. The description adds limited value beyond restating that two projections are involved; it does not explain what constitutes a valid projection or how to format them.

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 performs a cross-projection consistency check to confirm two projections originate from the same signed receipt. This specific verb-resource pairing distinguishes it from sibling verification tools that focus on single projections.

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 implies usage when you have two projections that need to be checked for shared receipt origin, but it does not explicitly contrast with alternatives like aps_verify_attribution_projection or provide when-not-to-use guidance. Usage context is implicit rather than explicit.

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