get_subscription

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

With no annotations provided, the description carries the transparency burden. It discloses that the system checks both current and legacy platforms automatically, and describes the response structure including the 'platform' field. It does not mention error cases or permissions, but for a fetch operation this is adequate.

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 longer than average but every sentence adds value. It starts with the core purpose, then the platform behavior, then the response fields – structured logically with no fluff.

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?

Given the tool's simplicity (1 parameter, no output schema), the description is remarkably complete. It explains the response with platform-specific fields and even distinguishes modern vs legacy formats, giving an agent full expectations.

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 has 0% description coverage, but the description thoroughly explains the 'reference' parameter as an ID or reference number, provides a concrete example, and clarifies that any identifier is accepted. This fully compensates for the missing schema documentation.

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 tool's function: 'Fetch a FastSpring subscription by its ID or reference number,' with a concrete example. It distinguishes itself from siblings by focusing on fetching a single subscription by identifier, not listing or line items.

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 implies usage when you have a subscription identifier and need full details. It does not explicitly name alternatives or exclusions, but the context is clear enough for an agent to choose this over list_subscriptions or get_subscription_line_items.

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