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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds value beyond that by disclosing default ordering (newest first), the record shape returned (status, amount, referring member, notes, dates) and the underlying GET /api/referrals call — useful for a tool with no output schema.

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 dense sentences: the first front-loads what the resource is and what comes back, the second enumerates the filter surface. No filler, though the trailing 'GET /api/referrals' is of marginal value to an agent.

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 enumeration of returned fields and default sort ordering fills an important gap, and the enum statuses are named. Pagination semantics are handled purely by the schema and not echoed in prose, which is a minor omission but acceptable given 100% schema coverage.

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%, with defaults, enums, bounds and pagination guidance (next_offset) already documented in the schema. The description only restates that filtering is possible across those dimensions and adds no format or syntax detail, so 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?

States a specific verb and resource (list referrals = people members referred) plus default ordering and returned fields, which disambiguates it from get_referral. It does not explicitly name a sibling tool, so it falls just 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?

The listed filters (program, status, member, query, created date) imply when to use this listing tool, but the description never says when to prefer get_referral, list_members, or list_rewards instead, nor any prerequisite context. Usage is inferable rather than stated.

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