icloud-mcp

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

No annotations provided, so description carries full burden. It excellently discloses merge-vs-replace semantics for each parameter (merges UIDs, replaces pendingActions, accumulates skip counts), but omits broader behavioral context like idempotency guarantees, error states, or what constitutes a 'run'.

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?

Single, dense sentence with zero waste. Front-loaded with the main action ('Update the digest state'), followed by parallel clauses mapping each parameter to its specific behavioral mode. Every phrase earns its place.

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 this is a state-management tool for what appears to be an email digest system (evidenced by 'smart unsubscribe' in schema), the description adequately covers the four parameters but fails to explain the domain concept—what a 'digest' is, what 'processed UIDs' refer to (email IDs?), or the overall lifecycle of the digest state machine.

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?

While schema has 100% coverage, the description adds crucial semantic meaning by specifying operation types (merge vs replace vs accumulate) that aren't fully explicit in the schema alone, helping the agent understand how each parameter transforms the existing state.

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 specific action (update) and resource (digest state), and explicitly distinguishes from sibling 'get_digest_state' by specifying this is a write operation that modifies state rather than retrieving it.

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?

Provides temporal context ('after a run') suggesting when to invoke, but lacks explicit guidance on when NOT to use this versus alternatives, and doesn't clarify the relationship with 'get_digest_state' (likely a read-before-write pattern).

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