arrangement_selection

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

With no annotations, the description carries the full behavioral burden. It does disclose useful return semantics: start/end ticks and the -1 means no selection. However, it does not explicitly state that the tool has no side effects, whether both start and end are -1 when no selection exists, or what happens if called with no current selection.

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?

A single sentence with the core meaning front-loaded and parenthetical detail kept minimal. Every word contributes value and there is no redundancy.

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 zero-parameter, no-output-schema getter, the description covers the essential semantic: current selection bounds in ticks and the no-selection sentinel. It could be slightly more explicit about the return format or the end-tick sentinel behavior, but it is otherwise adequately complete.

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?

The input schema has zero parameters, so there is nothing to document. The description instead adds value by defining the meaning of the returned values (start/end ticks and the -1 sentinel), which is the relevant semantic content for this tool.

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 identifies the resource (current timeline selection) and specifies its meaning via start/end ticks plus the -1 sentinel, so an agent can understand this is a state getter. It lacks an explicit verb like 'get' or 'returns', and it does not differentiate it from sibling arrangement_current or arrangement_select, but the phrase is specific enough to infer the purpose.

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?

There is no guidance on when to use this tool versus alternatives such as arrangement_current, arrangement_list, or arrangement_select. The read-only nature is implied but no selection context, exclusions, or alternative references are provided.

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