get_activity

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the description's '(read-only)' is redundant. It does add the useful context that data comes from Garmin Connect (open-world upstream), but the trailing 'Dates are YYYY-MM-DD' note is irrelevant to a tool that takes only an activity ID, so it adds noise rather than behavior insight.

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 short sentence, front-loaded with the core action, with no padding. The one flaw is that the parenthetical mixes a relevant fact (Garmin Connect) with an irrelevant one (date format).

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?

An output schema exists, so return structure need not be described, and the read-only profile is covered by annotations. Still, for a tool whose sole input is an opaque ID, the description leaves the agent guessing how to obtain that ID and how this differs from the many other activity-summary siblings.

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% and the single parameter 'activity_id' (integer or string) is never explained — no note on where to obtain it or on the integer/string duality. The only detail offered, date formatting, does not apply to any parameter in this schema.

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?

States a specific verb and resource ('Return activity summary, including basic splits'), which is enough to know it fetches one activity's summary. However, it does not differentiate itself from close siblings such as get_activity_details, get_activity_splits, or get_activity_split_summaries, so an agent cannot tell from the text alone when 'basic splits' is sufficient.

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 or when-not-to-use guidance, and no mention of the obvious alternatives (get_activity_details for full detail, get_activity_splits for granular splits). The only usage-adjacent statement is 'read-only', which is already in annotations.

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