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

readOnlyHint=true already tells the agent this is a safe read. The description adds real behavioral context beyond that: results are limited to *active* gifts, and at least one filtering term is mandatory, which means this cannot be used as a bare enumeration. Return format and pagination semantics are left unstated.

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?

Purpose and the required-term precondition are front-loaded, and the term-field enumeration is dense but each entry earns its place by teaching operators the schema does not. The single long comma-chained list is a wall of text, which keeps it out of 5 territory.

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 search tool with no output schema, it covers purpose, mandatory input, the term mini-language, and the underlying LGL endpoint. It omits response shape and pagination mechanics, though offset/limit in the schema hints at paging.

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 would be 3, but the description absorbs the semantics of the `terms` parameter: the schema merely says 'See the tool description for the available fields,' and the description then enumerates each field and its operator syntax (gt/lt/btw/in/ni, date formats). That is genuine added meaning above the schema.

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 and resource ('Search active gifts across the account') and gives two concrete usage examples (everything in a date range, or gifts to a fund/campaign). It does not differentiate itself from the sibling lgl_list_constituent_gifts, which is the likely confusion point, so it stops short of 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?

Clearly states how to invoke it (supply date/updated bounds and/or raw `terms`) and enforces a hard precondition ('At least one term is required'). It never names an alternative tool or a when-not condition, so it is clear context without routing guidance.

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