mhlb_get_coupon

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

Annotations cover readOnlyHint and openWorldHint, so the safety baseline is set. The description adds a genuinely valuable behavior note not derivable from annotations: that the returned text is third-party/untrusted and must be treated as data rather than instructions (injection warning). It does not describe the shape of the returned coupon, but that gap is modest.

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?

Two tight sentences. The purpose is front-loaded and the security caveat follows without padding; every clause 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?

For a 0-param, read-only tool with annotations already covering the safety profile and no output schema to explain return values, the description is nearly complete. Only the absence of any hint about the coupon's fields or the no-coupon return state keeps it from a 5.

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?

Zero parameters, so the baseline of 4 applies. There is nothing param-related for the description to clarify or compensate for.

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?

Specific verb+resource: 'Get the coupon currently applied to the account'. The word 'currently' scopes it to the applied state, which implicitly separates it from apply_coupon/remove_coupon siblings, though none are named explicitly.

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?

'if any' implies this may return nothing, giving minimal usage context. There is no explicit guidance on when to call this versus apply_coupon, remove_coupon, or the other get_* inspection tools.

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