list_groups

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

Annotations already declare readOnlyHint and idempotentHint, so the safe, repeatable read profile is fully covered. The description adds the 'all groups' scoping detail, useful for setting expectations about filtering. It does not mention pagination or ordering, but the output schema covers the return shape; there is 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 accomplish both core purpose and alternative routing with zero filler. Information is front-loaded: the primary function comes first and the alternative second. Every sentence earns its place.

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?

Given the output schema and the readOnly/idempotent annotations, the description covers what the agent needs for selection and safe invocation of a simple listing tool. Its one gap is recommending list_videos, which is not in the provided sibling set, and it omits pagination/filtering caveats. On balance it is nearly complete for the tool's complexity.

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 0 percent, and the sole 'rationale' parameter has no schema description; the tool description says nothing about it either. Because the description must compensate for low coverage but does not, it adds no information about how to fill the one argument. The parameter is optional and reasonably self-evident by name, which prevents a score of 1.

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 opening sentence 'List all video groups' names a specific verb and resource with an explicit 'all' scope, making the tool's function unambiguous. It also points to list_videos as the narrower per-group alternative, which reinforces what this tool is not. Clear enough to select correctly even before reading the 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?

The description explicitly says to use list_videos with a group_id when the goal is videos in a specific group, which is actionable routing guidance. It does not cover other grouping alternatives (e.g., create_group/delete_group), and the referenced list_videos is absent from the provided sibling list, so it cannot be a 5.

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