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

Annotations only declare it is a non-read-only, non-idempotent, non-destructive, closed-world write. The description goes well beyond that: it returns immediately, one statement may become database-current for Home while the rest remain Up next without extra pushes, and it does not verify phone display or delivery. It also discloses the capacity semantics of propositions_needed and consent behavior across runs.

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 purpose is front-loaded in the first sentence, and every subsequent sentence carries a distinct constraint (return behavior, non-verification, sibling prohibition, prerequisite, capacity semantics, consent). It is dense and slightly overpacked for a single-parameter tool, but there is essentially no 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?

An output schema exists, so return values need not be described, and the description still covers timing, persistence side effects, prerequisites, sibling boundaries, and consent. For a mutation with moderate behavioral subtlety, nothing an agent needs to invoke it correctly is missing.

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?

With a single parameter at 100% schema coverage the baseline is 3, but the description adds real meaning: statements should be genuinely useful and distinct, propositions_needed is a maximum rather than a quota, and agents must not invent extras to fill capacity. This clarifies intent beyond the schema's minLength/minItems/maxItems constraints.

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 concrete verb and resource: add one to three optional personalized reflections under Settings → Vibe Checks. It also explicitly names the sibling it must not be confused with (request_vibecheck), so an agent can route correctly. The purpose is embedded in a conditional clause rather than stated up front, which slightly blunts immediate clarity.

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?

It gives an explicit trigger ('when the person asks to stock reflections for later, or has explicitly authorized scheduled stocking'), an explicit prohibition ('Never call this to add follow-up asks after request_vibecheck'), and a prerequisite (call get_vibecheck_status first). It also clarifies that an active scheduled authorization removes the need for repeated consent. This is about as complete a when/when-not/alternatives statement as one could ask for.

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