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

Annotations already mark the tool as read-only and non-destructive; the description adds meaningful behavioral context about the 'signed' field (HMAC only when WEM issued it) and the 'verified is false' inferred-match caveat. It does not contradict the annotations.

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 first three sentences are focused and informative, but the rest of the description spends most of its length on shopping-tool routing and a sibling-specific warning (find_lowest_price). This is not appropriately concise for a one-parameter read-only lookup tool and dilutes the core message.

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?

Given the output schema exists, annotations cover safety, and there is only one well-described parameter, the tool-specific needs are covered: what it fetches, why, and the signed/verified edge cases. The extra sibling guidance is unnecessary for completeness, but nothing essential about this tool is missing.

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 schema already explains that id is the receipt id returned from verify_offer as receipt.id (wem-evr-...). The description mentions the same wem-evr-... format but adds nothing materially beyond the schema, so it stays at the baseline.

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 opens with a specific verb and resource: 'Fetch a WEM evidence receipt by id' and clarifies the unique artifact type (wem-evr-...). It also states the return purpose—'citation handle from a prior verify_offer call'—which distinguishes this receipt-lookup tool from the shopping/comparison siblings.

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 gives clear context for when to use this tool: to retrieve and cite a verification without repeating a claim. It also routes shopping-related queries away to sibling WEM tools and even warns against using find_lowest_price on a specific model name. However, the guidance is somewhat indirect for this specific tool rather than a crisp 'use when X, not when Y' statement.

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