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

Annotations already declare readOnly=true, idempotent=true, destructive=false, so the safety profile is covered. The description adds genuinely new behavior: it aggregates four record types and returns them newest-first, which the annotations do not convey. It stays silent on pagination depth or result-size behavior, keeping it from a 5.

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?

A single front-loaded sentence that states the trigger, the scope, and the ordering with no filler. Nothing could be removed without losing information.

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, annotations cover the safety profile, and all three parameters are documented, so the description only needs to convey scope and ordering, which it does. The one remaining gap is how to advance through a long history using the before cursor in practice.

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%, with contact_id, limit (default 20, max 100), and before all documented inline. The description adds no parameter-level information such as how to page backwards through history. Baseline 3 is appropriate when the schema carries all parameter meaning.

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 names a specific resource and scope: the full history with one person, aggregating notes, calls, activities, and tasks in reverse-chronological order. An agent can tell this apart from contacts.get or notes.list by the aggregation breadth. It does not explicitly name the sibling it replaces, so it falls short of a 5.

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?

"When the user wants the full history with one person" is an explicit use trigger that maps a user intent to this tool. No when-not conditions or named alternatives (e.g., contacts.get for a profile summary, notes.list for notes only) are given, so an agent must infer the boundaries.

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