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

Annotations provide no behavioral details beyond non-readOnly/non-destructive. The description adds significant context: normalization, deduplication, skipping unreachable/duplicate entries, plan cap enforcement, and requirement for a connected account. No contradiction with annotations.

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?

Two sentences: first covers main purpose and input methods, second covers behavioral traits. No filler, front-loaded with key 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?

The description covers input methods and behavioral traits well, but lacks mention of output/return value (e.g., count imported) or error handling. Given no output schema, a brief note on expected outcome would improve completeness.

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 0%, but the description explains the parameters: list_name (created if new), contacts array (with name, email, phone), and CSV text (header row auto-mapped). This adds meaning beyond the schema's type/constraint definitions.

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 action (import), the target (distribution lists/network), and the input (contacts via array or CSV). It distinguishes itself from siblings like import_guest_list by specifying 'your distribution lists (your network)'.

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 specifies the two input methods (contacts array and/or CSV text) and that list_name will be created if new. It provides behavioral context (normalizes, dedupes, skips unreachable/duplicate, respects plan cap) but does not explicitly contrast with siblings or state when not to use it.

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