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

readOnlyHint=true already covers the safety profile, and notably the description does not contradict it despite the underlying POST (a query POST is still a read). The description adds real behavioral context beyond the annotations: the return envelope { list, total } and the fact that full_details switches Contact/Gift queries to full records rather than the abbreviated view. It does not mention rate limits or pagination cost, which keeps it short of a 5.

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?

Four tight sentences with no filler; the scope of the tool is front-loaded before the conditions/return details and the API mapping trails at the end. Everything present is relevant, though the endpoint line (POST /api/<Resource>/Query) is the most expendable element.

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 read-only query tool with no output schema, the description supplies the missing return shape ({ list, total }) and the full_details behavior switch, so an agent can interpret the response without one. The main gap is sibling positioning versus the extensive list_*/search_* family, which is the most likely source of wrong-tool selection.

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%, so the baseline is 3, but the description adds meaning the schema does not carry: it points conditions at virtuous_get_query_options as the authoritative source of valid parameter/operator names, which is the single hardest thing to get right when calling this tool. The full_details note largely restates the schema description ('Contact and Gift only'), but the cross-tool reference is a genuine addition.

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?

States a specific verb+resource: runs a Virtuous query-builder query against one record type, and enumerates the record types (contacts, gifts, campaigns, projects, tasks, grants, pledges, recurring gifts, events). It also gives the concrete API mapping (POST /api/<Resource>/Query). However, it never distinguishes this generic query tool from the many per-resource siblings (virtuous_list_contact_gifts, virtuous_search_contacts, etc.), so an agent cannot tell from the description alone why it would pick this over a specialized list/search tool.

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 supplies one real workflow prerequisite: condition parameter/operator names must come from virtuous_get_query_options. That is useful routing, but there is no explicit when-to-use guidance and no when-not-to-use or named alternative against virtuous_search, virtuous_search_contacts, or the numerous list_* siblings. Usage is only implied by 'run a query-builder query'.

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