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

Beyond the annotations, it discloses the 0.1 SOL fee, the unsigned nature of the transaction, that keypair bytes never leave the device, and that value-moving results must be finalized locally. These are material behaviors that readOnlyHint, idempotentHint, and destructiveHint do not capture.

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 tool-specific first sentence is strong and front-loaded, but a large portion is generic SAP MCP context and execution guidance repeated in the schema description. References such as 'the Steve signed-transaction submit relay' are unexplained, so not every sentence earns its place.

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 a full output schema, 100% parameter documentation, and explicit payment/signing workflow, the agent has most of what it needs to call and handle the result. However, the description references tools not present in the sibling list and does not clarify the minimum fields needed for a meaningful registration.

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 each parameter already carries a meaningful description, so the baseline applies. The tool description adds no per-parameter semantics beyond a general warning not to include private key material.

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 opening phrase 'Hosted-safe unsigned builder for register_agent' names a specific verb, resource, and delivery mode, so an agent can tell this builds a registration transaction rather than executing one. The title and 'Pays the 0.1 SOL SAP protocol registration fee' reinforce the exact resource and scope.

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 explicitly routes the workflow: estimate cost first, pay/build, then finalize locally, and mentions alternatives such as sap_payments_call_paid_tool and sap_payments_finalize_transaction. It does not explicitly contrast with sibling builders like sap_build_agent_update_transaction or direct sap_register_agent, so it stops short of a 5.

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