lemon-squeezy-mcp

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

No annotations are provided, so the description carries full burden. 'Create' implies a write operation, but it doesn't disclose behavioral traits like permissions needed, whether it's idempotent, rate limits, error conditions, or what happens on success. The parenthetical about billing adds some context but insufficient for a mutation tool.

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?

Single sentence, front-loaded with the core purpose. The parenthetical adds useful context without verbosity. No wasted words, though it could be slightly more structured (e.g., separating purpose from context).

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 mutation tool with no annotations and no output schema, the description is incomplete. It doesn't explain what the tool returns, error handling, or important behavioral aspects like side effects. The 100% schema coverage helps with parameters, but overall context is lacking for safe 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?

Schema description coverage is 100%, so the schema fully documents the three parameters. The description doesn't add any meaning beyond what's in the schema (e.g., no examples of 'action' values, no explanation of how 'quantity' interacts with billing). Baseline 3 is appropriate when schema does the heavy lifting.

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 action ('create') and resource ('usage record for a subscription item'), with the parenthetical adding context about usage-based billing. It distinguishes from siblings like 'get_usage_record' (read) and 'create_customer' (different resource), though it doesn't explicitly contrast with them.

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 explicit guidance on when to use this tool versus alternatives. The description implies it's for billing-related usage tracking, but doesn't mention prerequisites, constraints, or when to choose other tools like 'update_subscription' for different modifications.

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