Subscribe Digest

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

Beyond annotations (all false), the description discloses the double opt-in flow, one-click confirm link, one-click unsubscribe, and that it sets no marketing flag. It also specifies return shape ({ok, sent, message}). These are behavioral traits not derivable from annotations or schema alone.

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, with the core purpose in the first clause and additional details structured around consent and usage. While slightly long, each section earns its place; no redundant or vague filler.

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 complexity of a consent-based subscription flow, the description covers purpose, trigger conditions, consent mechanics, return value, and an explicit alternative. The output schema exists, so return details are partially covered, but the description still enriches with enough context for full 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 coverage is 100%, so baseline is 3. The description adds semantic nuance by reiterating that email is required, must be explicitly shared, and that a confirm link is sent. It clarifies source is an optional tag, which enriches the schema's existing property descriptions.

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 a specific verb ('Subscribe') and the resource ('DC Hub's FREE weekly digest'), and outlines what the digest contains (DCPI movers, new facilities, new deals & news). It also distinguishes this tool from other subscription tools by emphasizing the 'ONE call' nudge aspect, making it unambiguous what this tool does.

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?

Explicit when-to-use guidance is provided: 'Only call once your human shares their email and wants a weekly email.' It also tells when not to use it (before consent) and recommends preferring this over a raw API call. This clearly frames usage conditions.

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