get_subscription

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

With no annotations, the description must carry the behavioral disclosure burden. It includes a strong instruction to never fabricate data on failure, which is a valuable transparency note about error handling. However, it says nothing about whether the operation is read-only, what permissions are needed, or what the response contains on success. The warning partially compensates for the lack of annotations.

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 concise: one sentence stating the purpose followed by a clear, important warning. There is no redundant fluff, and the warning is front-loaded enough to catch attention. It could be slightly more structured, but it is appropriately sized for a simple tool.

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 tool with no output schema, the description covers the basic purpose and includes a relevant behavioral warning. However, it does not mention what the tool returns (though 'detailed information' implies a response), nor does it specify any prerequisites beyond the required parameter. Given the low complexity, this is adequate but not comprehensive.

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 describes the single parameter subscription_id as a string 'Subscription ID' with 100% coverage. The description adds no additional meaning or context about the parameter—no format, example, or caveats. Since the schema already fully documents the parameter, the baseline of 3 is appropriate.

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 states a clear verb ('Get') and a specific resource ('subscription service'), making the tool's purpose obvious. It implies a single subscription rather than a list, which distinguishes it from list_subscriptions, but does not explicitly name alternatives. The warning about not fabricating data is additional context but does not affect purpose clarity.

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?

No guidance is given on when to use this tool versus its siblings. The description does not mention that this should be used when a specific subscription_id is known, nor does it contrast with list_subscriptions or list_subscription_catalog. The agent is left to infer usage from the parameter schema alone.

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