Compare activities

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered. The description adds genuinely new behavioral context: fetches in parallel, returns compact detail, and mirrors get_activity's field set — all useful for an agent reasoning about cost and output shape.

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?

Two tight sentences: the capability and its output shape come first, then the usage examples and the ID-sourcing hint. No filler, no repetition of the title.

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 no output schema, the description wisely anchors the return value to get_activity and labels it 'compact', which is enough for an agent to set expectations. Minor gaps remain: result ordering relative to the input IDs and behavior on an invalid or inaccessible ID are unstated.

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 min/max item bounds and the numeric-ID pattern are already documented. The description still adds value by telling the agent where the IDs come from ('get the IDs from search_activities'), which is not derivable from the 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 ('side-by-side compact detail for 2-5 activities') and explicitly ties the output shape to a known sibling ('same fields as get_activity'), which lets an agent distinguish it from get_activity and summarize_activities without opening a schema.

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?

Gives concrete triggering examples ('compare my last two long runs', 'how did this race compare with last year's') and routes the agent to search_activities as the ID source. It stops short of an explicit exclusion such as 'for a single activity use get_activity', but the 2-5 range makes the boundary largely self-evident.

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