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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=true, and openWorldHint=true. The description adds valuable behavioral detail beyond those flags: duplicate creation risk on repeat calls, no automatic invitation, and the underlying endpoint. It does not explain the destructive implication or auth requirements, but it meaningfully supplements the annotations.

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?

Three short sentences, front-loaded with 'WRITE' and the core action. Every sentence carries useful information: mutation type, idempotency warning with alternative tool, invitation caveat, and endpoint. 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 13-parameter write tool with no output schema, the description covers the most important behavioral risks (duplicate creation, no invitation) but omits what the response returns and how to identify the created customer. It also leaves the status default and external_id linkage unexplained. Adequate but with clear gaps given the tool's complexity.

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?

The tool has 13 parameters with only 31% schema description coverage, so the description should compensate by explaining required or important fields. Instead, it provides no parameter-specific guidance at all — not for the required name/email/phone, nor for the status enum or external_id linking. The schema does constrain required fields, but the low coverage gap is unaddressed.

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: 'create a new customer (retailer) account record.' The 'WRITE' prefix and endpoint make the mutation nature immediately clear, and naming markettime_list_customers distinguishes it from the sibling read 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?

Explicitly tells the agent to search with markettime_list_customers by name before calling, because the operation is not idempotent. It also clarifies that no invitation is sent automatically, which is useful context. It lacks broader 'when not to use' guidance, but the deduplication prerequisite is the key selection condition.

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