List items on a todo list

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

Annotations already declare read-only, idempotent, non-destructive behavior, so the safety profile is covered. The description goes further with implementation context an agent cannot get elsewhere: it names the underlying WS command (`todo/item/list`), discloses that the status filter is applied client-side in Python, and warns that HA's response shape has varied across versions. Not a 5 only because return-format details are partly redundant with the existing output schema.

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?

Well front-loaded and organized into purpose, mechanism, 'Use when/Not for', and 'Returns' sections, so every part is scannable. Slight deduction because the parenthetical about version-varying response shapes, while useful, sits mid-paragraph and could be tightened.

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 the description need not enumerate return fields, yet it still summarizes them helpfully. Combined with annotations covering safety and a complete schema, an agent has everything needed to call this tool correctly.

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 100%, so both parameters (including the enum-like `status` values and `entity_id` example) are already fully documented in the schema, establishing the baseline of 3. The description confirms status filtering happens post-fetch in Python, which adds mild behavioral nuance but little that the schema does not already state.

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 opens with a specific verb+resource ('List items on a todo list') and immediately clarifies scope with 'optionally filtered by status.' It also explicitly distinguishes itself from the closest sibling by name (`todo_list_todo_lists`), so an agent can select it without opening any schema.

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?

Uses explicit 'Use when' and 'Not for' framing, naming the exact alternative tool (`todo_list_todo_lists`) for the confusingly similar case of listing todo entities. This is precisely the when/when-not/alternative guidance the dimension rewards.

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