Subscribe Digest

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

The description discloses consent behavior in detail: double opt-in, one-click confirm link, one-click unsubscribe, no marketing flag set, and the returned shape. This goes well beyond the minimal annotations and tells the agent exactly what side effects to expect.

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 dense but well-organized, front-loading the purpose and then providing consent caveats, trigger conditions, params, return value, and a preferred alternative. It is longer than strictly necessary but every sentence carries meaningful selection or behavior information.

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 annotations, input schema, and output schema, the description covers everything needed: when to call, consent side effects, parameter expectations, return shape, and an alternative. Nothing critical is missing for an agent to invoke this correctly.

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 coverage is 100%, so the schema already documents both parameters. The description adds a small amount of context by emphasizing the email must be explicitly shared and mentioning source is an optional tag, but it mostly restates what the schema provides.

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 specific verb and resource: subscribing a human to DC Hub's weekly digest, and explains exactly what the digest contains. It is clearly distinguishable from the many sibling data-query tools and even contrasts itself with hand-building the POST endpoint.

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 gives an explicit precondition: only call once the human shares their email and wants a weekly email. It also provides a clear alternative by saying to prefer this tool over hand-building POST /api/v1/opt-in/request, which gives the agent actionable selection guidance.

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