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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false. The description adds useful behavior: returns null if the member is not enrolled. This supplements the annotations without contradicting them. No further traits like auth needs or rate limits are mentioned, but the added context is sufficient.

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?

The description is a single sentence of 20 words, front-loaded with the verb and resource. It is concise, no filler, and every phrase adds value.

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?

Given the presence of an output schema, the description adequately covers return specifics (enumerated fields and the null case). For a read-only tool with rich annotations, this is complete and sufficient.

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% with a clear description for accountId. The description does not add extra meaning beyond confirming this is a member ID. Baseline of 3 is appropriate as the schema handles parameter documentation.

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 clearly states it retrieves a member's current loyalty balance, enumerating key components (points, stamps, credits, lifetime totals, active membership tier). It also distinguishes from sibling tools like earn_loyalty_points, issue_rewards, get_membership_tier, and get_member_profile by focusing on the full balance for an enrolled member.

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 implies usage for retrieving comprehensive loyalty data but does not explicitly state when to use this tool versus alternatives (e.g., get_membership_tier for tier-only queries, or earn_loyalty_points for earning operations). No 'when not to use' or exclusion criteria are provided.

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