get_activity_split_summaries

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

Annotations declare readOnlyHint=true and openWorldHint=true, so safety is covered, but the description adds nothing beyond that: it does not say what a 'summary' aggregates, how the summary differs from raw splits, or whether results are grouped by lap/segment.

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?

It is a single front-loaded phrase with zero filler, but at the cost of under-specification rather than genuine concision. There is no wasted text, but also not enough text to be useful.

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?

The tool has no output schema, so the description should carry at least some sense of what is returned and how it relates to get_activity_splits, yet it does neither. For a read tool whose only purpose is its return shape, the definition is incomplete.

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% for the single activityId parameter, so the schema carries the parameter documentation. The description adds no additional meaning (e.g., whether an invalid or missing activity id errors or returns empty), so the baseline of 3 applies.

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 is essentially a restatement of the tool name: 'get_activity_split_summaries' becomes 'Summaries of an activity's splits.' It names the resource but gives no verb and no way to distinguish it from close siblings like get_activity_splits or get_activity_typed_splits, leaving 'summaries' undefined.

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 when-to-use guidance at all. With three closely related split tools in the sibling list (get_activity_splits, get_activity_typed_splits, get_activity_split_summaries), the absence of any routing rule forces the agent to guess among them.

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