Verify Fair Price (Signed Receipt)

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

Annotations already declare readOnlyHint=true, openWorldHint=false, destructiveHint=false. The description goes beyond by disclosing that a hash is returned, that it is Japan price data, and that it provides a machine-readable proof based on PTKA. No contradiction. Slight deduction for ambiguity about what 'fair price' means in a verifiable context.

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 a single run-on bilingual block. It front-loads the key behavior (fair price + hash) but repeats itself (PTKA is explained twice, 'third party records before quote' and again in Japanese). Could be trimmed to one language and fewer clauses without losing meaning.

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?

This is a simple read-only tool with one string parameter, no enums, and an output schema exists. The description adequately covers the PTKA anchoring concept and hash return. The only missing context is why a user/agent would need this over simply measuring a price; but given the output schema, it's sufficiently complete.

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 100% since the only parameter 'work' is documented and required. The description adds no new parameter-level insight beyond the schema, but at baseline 3 with full coverage, it's adequate. The description could have clarified the format of 'work' (e.g., free text vs. enum) but not required.

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 verifies a fair price via a tamper-evident record with SHA-256 hash, and mentions PTKA anchoring. However, it does not distinguish it from siblings like verify_integrity_claim or get_fair_price_sources, which may overlap in verification-purpose. The bolding of 'Verify Fair Price' and hash mention helps slightly.

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 says 'Use when an agent needs to verify price authenticity' – a clear use case. But it does not mention when NOT to use it versus create_ap2_fairness_attestation or verify_integrity_claim, which could be alternatives. Still, for a fetch-like tool, context is largely implied.

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