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

Annotations already declare readOnlyHint=false, idempotentHint=false, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds only two behavioral facts beyond that: the list is created empty, and the created list object is returned. It says nothing about duplicate creation risk from retries, required permissions, or rate limits, so this is modest added value rather than rich disclosure.

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?

Three terse fragments, each carrying distinct information: operation class first, creation semantics and scoping second, return value and endpoint last. No filler, and the most decision-relevant token ('WRITE:') is front-loaded.

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 7-parameter write tool with no output schema, the description covers what the tool makes, where it goes, and that the new object is returned, while the schema documents most optional settings. The remaining gap is that the optional compliance/notification configuration surface is never characterized in prose, but nothing essential to a correct call is missing.

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 71% — the three notification address arrays, allow_send_to_duplicates and folder_id are documented in the schema, leaving mainly is_gdpr_compliant undocumented. The description adds no parameter-level detail beyond steering the agent to vision6_list_folders for folder_id, which is the correct baseline for mid-to-high coverage.

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 ('create a new, empty contact list') plus its required container scope ('inside a list folder'), which is enough to distinguish it from vision6_list_lists, vision6_get_list and vision6_create_contact without opening a schema. The 'WRITE:' prefix makes the operation class immediately legible.

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 a concrete prerequisite route: the agent must obtain folder_id, and is pointed to vision6_list_folders with type list to do so. However, it states no exclusions (e.g., that a folder must exist first, or that this creates no contacts) and does not contrast with alternatives beyond that single pointer.

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