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

Annotations only carry openWorldHint and idempotentHint, so the description usefully supplies the mutation semantics ('WRITE:') and the real-world effect on the payment link. It does not say what happens if the request is already enabled (error vs. no-op), which is the one behavior an agent would still want confirmed.

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?

One front-loaded sentence beginning with the mutation marker and the verb, followed by the endpoint. No filler whatsoever.

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 single-parameter mutation with annotations covering idempotency and open-world scope, the description covers purpose and effect adequately. The missing piece is the already-enabled case, which matters given idempotentHint=true.

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?

Only one parameter and schema coverage is 100%, so the schema already documents payment_request_id fully. The description adds no format or lookup guidance beyond that, 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 ('enable a previously disabled payment request') plus the concrete outcome ('its link accepts payments again'), and the WRITE prefix plus endpoint make it trivially distinguishable from the disable sibling.

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 precondition 'previously disabled' implicitly tells the agent when this applies, and the sibling set makes the alternative (instamojo_disable_payment_request) obvious. It never names the alternative or states when not to use it explicitly, so it stops short of 5.

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