get_activity_streams

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

With no annotations, the description carries the full burden and does so unusually well. It discloses downsampling to ~200 points, the return of min/max/mean per stream, and the deliberate non-return of full per-second data with a concrete rationale. This gives an agent accurate expectations about output shape and data volume.

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 layout is clear: purpose sentence, Args section, then Returns section. The explanation about coaching shape is slightly editorial but earns its place by clarifying why the data is truncated.

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?

Given only two parameters and no output schema, the description covers input format, defaults, valid options, output summary, and a key limitation. Nothing critical is missing for an agent to invoke it correctly.

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%, so the description must compensate, and it does. It provides a concrete example for activity_id and enumerates valid stream names with defaults and alternatives, giving an agent everything needed to construct valid arguments.

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 ('Get time-series streams for an activity') plus the downsampling qualifier. It is distinct enough from siblings like get_activity, but it does not explicitly name or contrast any sibling, so it falls just short of full differentiation.

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?

The description gives helpful context about default stream types and explains why full per-second data is intentionally omitted, which implies when the tool is appropriate. However, it never explicitly says when to prefer this tool over get_activity or another sibling, nor does it provide any exclusion criteria.

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