get_subscription_contract

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

No annotations are provided, so the description carries the full burden. 'Fetch' clearly indicates a read-only, non-destructive operation, adding some behavioral transparency. However, it does not disclose error behavior, response format, or any prerequisites beyond the ID, which are important for a tool with no annotation support.

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 a single, front-loaded sentence of eight words. It states the action and the resource with no waste, making it highly concise and well-structured.

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 simple get-by-ID tool with one well-documented parameter and no output schema, the description is complete. It adequately implies the return value (the subscription contract) and does not need to explain complex behavior. The sibling tool list provides further context if needed.

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 input schema has 100% coverage: the 'id' parameter includes a description and example format. The description itself adds no parameter information beyond what the schema already provides, so it meets the baseline but does not exceed it.

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 fetches a specific subscription contract by ID, using a specific verb ('Fetch') and resource ('subscription contract') with the scope ('by ID'). This distinguishes it from the sibling tool get_subscription_contracts, which presumably lists contracts.

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 when to use this tool: when you have a specific ID and need a single contract. It does not explicitly mention alternatives or exclusions, but the opposed sibling get_subscription_contracts provides context for list-vs-single usage. The guidance is clear enough for a simple fetch operation.

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