set_allowlist_mode

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

With no annotations, the description carries the full burden and does well: it explains what each mode does (blocks unlisted hosts before first fetch, blocks unlisted payees before signing) and requires an agent key. It does not specify immediate persistence effects or return behavior, but the core behavioral traits are disclosed, adding value beyond the schema.

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 sentences, front-loaded with the main purpose, then explains modes, points to a related tool, and notes the auth requirement. Every sentence earns its place, with no fluff or repetition.

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 setter with one parameter, no output schema, and no annotations, the description is exceptionally complete. It covers all enum semantics, the default state, the relationship to allowlist entry management, and the required agent key. Nothing essential is missing for correct invocation.

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 schema only lists the enum values without explaining them. The description enriches each value (off allows any vendor, host blocks unlisted hosts, vendor blocks unlisted payees, both enforces both), giving the agent a clear understanding of what each mode actually enforces. This is a significant addition beyond the schema's bare coverage.

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 the verb 'set' and the resource 'agent's merchant-allowlist enforcement mode', distinguishing it from sibling get_allowlist_mode and add_allowlist_entry. It also enumerates the specific modes and their effects, leaving no ambiguity about the tool's function.

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 provides clear context for when to use this tool (to change enforcement mode) and explicitly directs entry management to add_allowlist_entry. It does not explicitly mention 'use get_allowlist_mode to check current mode' but the set/get distinction is implied by the sibling context, making this a minor gap rather than a major omission.

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