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

Annotations already declare readOnlyHint=false, destructiveHint=true, openWorldHint=false, so the safety profile is covered; the description goes further by disclosing a hard failure mode (no fallback to inbox on a bad project name) and the Pro-tier requirement. Doesn't discuss whether the call is idempotent or what happens on duplicate names, which keeps it at 4.

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?

Four tight sentences, front-loaded with the verb and platform, then prerequisites, then the risky parameter behavior, then the return value. No sentence is filler and the failure warning sits right after the parameter that triggers it.

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 little explanation, and the description still names the returned task id. For a 7-parameter creation tool it covers platform prerequisite, default routing, error behavior, and the required-name-only constraint — everything an agent needs to call it without a failed attempt.

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 baseline is 3; the description earns above that by adding semantics the schema can't express — that `project` must match an existing project exactly and fails rather than defaulting. It says nothing extra about note, due_date, or the ignored `confirm` flag, which the schema already handles.

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?

States a specific verb and resource ("Creates a task in OmniFocus on this Mac") and scopes it to a concrete platform, which lets an agent separate it from todoist_create_task, todo_create_task, and create_reminder purely on the name-plus-description.

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?

Gives explicit preconditions (OmniFocus Pro required; free tier blocks automation), the default behavior without `project` (inbox), and a named prerequisite tool to call first (`list_omnifocus_projects`) so the agent is routed away from a predictable failure.

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