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

The annotations already declare readOnlyHint=true, so the safe-read profile is covered. The description adds the per-gift field shape (useful since there is no output schema) and the underlying endpoint, but says nothing about result volume, pagination behavior beyond the schema defaults, or what an empty result means.

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 tight sentences: the field list and the sibling routing are front-loaded, and nothing is redundant. The trailing 'Virtuous: GET /api/Gift/ByContact/{contactId}' is marginal padding for an agent that already has the schema.

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?

There is no output schema, and the description compensates by enumerating the returned gift fields. All five parameters carry schema descriptions, so the definition covers both the call and the expected payload adequately for a simple list tool.

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%, so skip, take, sort_by, descending and contact_id are all already documented in the schema. The description adds no parameter-level meaning beyond exposing contactId in the endpoint path, so the baseline 3 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?

Specific verb + resource ('List a contact's giving history') with the returned fields enumerated (gift id, type, date, amount, segment, batch). It also names the sibling it is not (virtuous_get_gift), so an agent can distinguish it from the detail-retrieval tool 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?

It explicitly routes the agent to virtuous_get_gift for designations and full detail, which is a clear alternative with a condition. It stops short of stating prerequisites (e.g. the contact must exist) or when to prefer the search/query siblings, so it is clear context rather than a complete when/when-not matrix.

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