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

The annotations already declare readOnly=false, idempotent=true, destructive=true, and openWorld=false. The description adds useful context that phone and email are saved but never returned, and it scopes out updates. However, it does not explain the destructiveHint implication or expand on idempotency beyond what the requestId schema already says.

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 three short sentences and is front-loaded with the trigger condition. Each sentence contributes distinct information: usage, return/privacy behavior, and exclusion. There is no filler.

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 simple create tool with rich schema descriptions, annotations, and an output schema, the description covers the trigger, exclusion, and sensitive return behavior. It leaves the destructive annotation unaddressed, but the schema and annotations already carry most operational details.

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%, and the schema fully documents all six parameters, including requestId idempotency and gymId default behavior. The description adds no parameter-level meaning beyond noting that phone and email are stored but omitted from the response, so the baseline is appropriate.

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 states a specific verb and resource: 'add a new member to a gym.' It also distinguishes itself from the update workflow with 'Not for changing an existing member,' so an agent can identify the tool without opening the 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 gives an explicit trigger: 'Use this when someone asks to add a new member to a gym.' It also provides a clear exclusion for changing an existing member, though it does not name update_member directly or discuss duplicate handling beyond the schema's requestId field.

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