Icu Update Activity Streams

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

Annotations already declare destructiveHint=true, readOnlyHint=false and idempotentHint=false, so the safety profile is carried by structured data. The description still adds value by specifying what is destroyed ('overwrites existing stream data') and what payload types are accepted, which goes beyond the boolean hint. It does not cover permissions/auth or partial-vs-full replacement semantics.

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 short sentences plus a parenthetical; the destructive warning is front-loaded and nothing is wasted. 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?

An output schema and rich annotations exist, so the description needn't explain returns or safety. It covers purpose, format, and destructiveness, but leaves open whether the upload replaces all streams or merges with existing ones — a meaningful gap for a destructive write.

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%, so all three parameters are already documented, including the 'json'/'csv' format enum in prose. The description's 'Accepts JSON array or CSV' largely duplicates the schema rather than adding format or shape detail, so baseline 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?

States a specific verb and resource ('Upload raw time-series streams ... onto an existing activity') with concrete examples of stream types. It also explicitly distinguishes itself from the read counterpart get_activity_streams, so an agent can separate the two without opening either 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?

Names the read sibling as the alternative and makes the write/read split explicit, plus warns the operation overwrites existing data, which is a strong usage cue. It does not address related write siblings such as icu_update_activity (metadata edits) or when a caller should prefer a full file upload (icu_download_fit_file inverse), leaving some routing inference to the agent.

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