get_activity_split_summaries

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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the description's 'read-only' is redundant. Beyond that, it adds only 'Garmin Connect' and an irrelevant date-format note; it says nothing about what a split summary contains, whether splits are per-lap or per-segment, or any retrieval constraints.

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 short and front-loads the purpose, which is good. However, the parenthetical includes a date-format instruction that is irrelevant to this tool's schema, so not 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?

With an output schema present, the description needn't explain return values, and annotations cover safety. But for a tool sitting among several split-related siblings, it lacks the one piece of context an agent needs: what distinguishes these 'split summaries' from get_activity_splits and get_activity_typed_splits.

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% for the single required parameter activity_id, so the description should compensate but does not. The only parameter-related sentence ('Dates are YYYY-MM-DD') does not apply to activity_id and may actively mislead an agent into expecting a date parameter.

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 ('Return activity split summaries'), making the basic operation clear. However, it does not differentiate this from sibling tools like get_activity_splits or get_activity_typed_splits, leaving ambiguity about what 'summaries' means in contrast to those alternatives.

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 the closely related get_activity_splits or get_activity_typed_splits. The only contextual note is 'Garmin Connect, read-only' and a date-format remark that is irrelevant since the sole parameter is activity_id, not a date.

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