Get one voucher

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is clear. The description adds the behavioral detail that the result includes postings and attachments, which goes beyond the basic fetch semantics but doesn't disclose any additional side effects, permissions, or rate limits. This is consistent with the annotations and adds moderate context, but not rich behavioral 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?

The description is a single, front-loaded sentence that states the core action and the key included data. It is concise with no filler or redundancy.

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 simple single-fetch operation, the description covers the essential information: what is fetched (voucher by id) and what is included in the result (postings and attachments). The schema handles parameter details and annotations cover the read-only nature, so the description is sufficiently complete for an agent to invoke it correctly.

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%, with both parameters already having descriptive text, including a helpful note on tenantId referencing reai_use_tenant and reai_whoami. The tool description itself adds no parameter-specific meaning beyond what the schema provides, so it meets the baseline three for high coverage.

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 explicitly states the verb ('Fetch'), the resource ('a single voucher by id'), and the scope ('including all its postings and attachments'). This clearly distinguishes it from sibling tools like reai_list_vouchers, which list multiple vouchers, and reai_list_postings, which list postings separately.

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 does not explicitly name alternatives or state when not to use the tool. However, the phrase 'by id' clearly implies this is for fetching a specific known voucher, and the sibling names like reai_list_vouchers suggest the alternative for listing. That said, there is no explicit 'use this instead of...' guidance, so the usage context is only implied.

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