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

readOnlyHint=true already tells the agent this is a safe non-mutating read, so the bar is lower. The description adds the return-content scope (designations, premiums, custom fields), but says nothing about error behavior for a missing gift id, authentication requirements, or rate limits.

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?

Two compact sentences, with the verb and scope front-loaded and the endpoint reference trailing as a cheap supplementary cue. The long field enumeration earns its place only because no output schema exists, but it does make the sentence dense.

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?

With no output schema, the field enumeration is the only source of return-shape information, and it covers contact, amount/currency, batch, segment, designations and custom fields thoroughly. The remaining gap is the absence of any error/not-found behavior for an invalid gift id.

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 description coverage is 100% and gift_id is documented as a positive integer in the schema itself, so the baseline of 3 applies. The description adds no format, range, or lookup-hint meaning beyond what the schema already states.

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 states a specific verb and resource ('Fetch one gift') and enumerates the fields returned, so the agent knows exactly what record shape comes back. It is distinguishable from the listing sibling (virtuous_list_contact_gifts) by the singular 'one gift in full', but it never names that sibling explicitly, so it stops short of a 5.

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?

Usage is only implied: 'Fetch one gift in full' suggests retrieving the complete detail record for a known gift id, contrasted with the list_contact_gifts sibling. There is no explicit when-to-use, when-not-to-use, or prerequisite statement, leaving the agent to infer the decision rule.

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