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 a non-obvious behavioral trait: the call performs a NEW live fetch of the target URL right now, not just a replay of stored data. It also discloses the access model ('public-by-id: anyone holding the receipt_id can re-check it'), which is a meaningful privacy/sharing property. It still doesn't state whether the fresh fetch can fail or cost anything, or how failures surface.

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?

Three sentences, front-loaded with the primary action and the fresh-recheck twist before the usage guidance. Every sentence contributes, though the parenthetical about CDN caches and the final sharing sentence make it slightly denser than needed.

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?

Covers purpose, triggering conditions, the live-recheck behavior, and the sharing model — good coverage for a one-parameter tool with no annotations. With no output schema, however, the description never says what a receipt actually contains or what the recheck result looks like, which an agent reasoning about the return value would want.

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% and the single parameter's format ('hex string returned by verify_write') is already documented in the schema. The description reinforces the provenance of the ID but adds no new syntax or constraint beyond it, so the baseline 3 for schema-documented params applies.

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?

Names a specific verb and resource ('Fetch a receipt ... plus a FRESH recheck') and explains what the receipt is and where it came from (verify_write), which cleanly separates it from the sibling verify_write that produces receipts. An agent can tell the two apart 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 two concrete triggering conditions — the write was still propagating (CDN caches, eventual consistency), or an operator asks for proof of a past write. It names the producing tool but never says when this is the wrong choice (e.g., no receipt exists yet, or when to just re-run verify_write instead), so the when-not side is missing.

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