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

Annotations already declare non-destructive and idempotent behavior, yet the description adds real value: archiving preserves memberships elsewhere, and the UI-menu analogy signals this is the same operation the product exposes. It repeats the idempotency-key retry rule already in the schema and omits whether archive is reversible.

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 tight sentences, operations front-loaded, side effect in a parenthetical, retry rule last. No filler or restated schema detail beyond what is needed.

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?

For a small mutation tool with annotations and no output schema, it covers the main paths, but since only list_id and idempotency_key are required, the description never says that at least one of name/archived must be passed nor how the two interact in a single call.

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 description coverage is only 25% (only idempotency_key documented), so the description must compensate — it does, explaining archived: true's effect and equating name with rename. list_id is self-evident; what remains unstated is whether name and archived can be combined and what happens if neither is supplied.

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 — renames or archives a contact list — which cleanly separates it from siblings like create_contact_list, edit_contacts, and edit_contact_tag. The scope (the list entity itself, not its members) is unambiguous.

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?

Makes clear this is the tool for renaming and archiving a list and clarifies archive semantics (people stay in their other lists). It also gives retry guidance, but names no explicit alternative or precondition (e.g., that unarchiving also goes here).

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