subscribe_digest

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

The description discloses behavioral traits beyond annotations: it triggers an email, involves double opt-in, is consent-safe, and sets no marketing flag. Annotations only indicate readOnlyHint false and destructiveHint false, so the description adds valuable context about the subscription flow and consent requirements.

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 verbose with colorful phrases like 'the nudge that pulls your agent back when the data moves,' which add flair but not essential information. It is front-loaded with purpose but could be more concise without losing meaning.

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 complexity (subscription with opt-in), the description covers when to call, behavior, return format, and consent. No output schema exists, but the description mentions returns {ok, sent, message}. This is sufficient for basic usage, though it omits idempotency or error handling details.

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, so the description must compensate. It only states 'email (required)' and 'source (optional tag)', which is minimal. No details on email format or valid source values are provided, leaving much ambiguity.

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 subscribes a human to a weekly digest about market changes. It uses specific verb 'subscribe' and resource 'digest', distinguishing it from sibling tools like set_market_alert or set_site_alert. However, it does not explicitly differentiate from all siblings, missing a direct comparison.

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 explicitly states when to call ('only once your human shares their email and wants a weekly email') and provides an alternative ('prefer this over hand-building POST /api/v1/opt-in/request'). It also explains the double opt-in process, giving clear usage context.

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