timeline_create_group

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

With no annotations, the description carries the full behavioral burden. It discloses meaningful constraints (groups cannot be nested, names must be unique), the exact return structure, and a concrete example. It still does not state reversibility, permission requirements, or what happens if the range is invalid, but it provides substantially more behavior than most bare definitions.

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?

The description is front-loaded with the core action and constraints, then provides the return shape and one concrete example. Every sentence adds useful information with no repetition or filler.

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 three-parameter mutation tool with no annotations and no output schema, the description covers purpose, constraints, return shape, and an example. That compensates well for missing structured fields. A minor gap remains around side effects or undo behavior, which would matter for a timeline mutation.

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 100%, so the baseline is 3, but the description adds value by explaining that first and last define an inclusive contiguous range of top-level items. The example further clarifies expected item references and the role of name. It stops short of documenting edge-case parameter behavior such as what happens when first equals last.

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 states a specific verb and resource: grouping a contiguous range of top-level timeline items. It also clarifies scope with 'first..last inclusive' and constraints like non-nesting, so the agent knows exactly what operation is performed. It does not explicitly differentiate from siblings such as timeline_ungroup, which keeps it from a 5.

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?

Usage is implied by the contiguous top-level range constraint, but the description does not say when to prefer this tool over alternatives like timeline_ungroup or timeline_set_group_collapsed. It also omits when-not conditions or prerequisites. The example helps but does not constitute explicit usage guidance.

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