mhlb_get_subscription_settings

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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true), but the description adds genuinely non-structured behavior: the returned text is third-party authored and untrusted, and should be treated as data rather than instructions. That prompt-injection warning is high-value context an agent cannot derive from the annotations or empty schema. It stops short of 5 only because return format/pagination are not addressed.

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 with no filler: the first front-loads what is fetched and what it contains, the second carries the security caveat. 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 zero-parameter read tool with no output schema, the description covers both what the tool returns (recurring-ordering flag and terms) and the critical handling constraint for that content. Nothing needed to invoke or interpret the result is missing.

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 takes zero parameters, so the schema carries no semantics to compensate for; per the rubric a 0-parameter tool has a baseline of 4. The description adds nothing parameter-related because there is nothing to add.

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 names a specific verb and resource ('Get the account's subscription configuration') and further specifies the payload ('whether recurring ordering is on, and its terms'), so an agent knows exactly what it retrieves. It does not explicitly differentiate itself from the write-side sibling mhlb_set_subscription_enabled, keeping it just short of a 5.

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?

Usage is implied — read subscription configuration when you need to inspect the account's recurring-ordering state — but there is no explicit when-to-use, when-not-to-use, or pointer to alternatives such as mhlb_set_subscription_enabled or mhlb_list_subscriptions. Adequate but leaves routing to inference.

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