last_activity

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

No annotations are present, so the description carries the full burden. It fails to disclose that the tool is a read operation (likely non-destructive), what side effects (if any) occur, or any constraints like data freshness. The word 'summary' hints at returned content but lacks behavioral specifics.

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 extremely short (one phrase). While it is concise, it sacrifices informativeness. It could include more context (e.g., 'Provides a brief summary of the most recent workout') without harming conciseness. Every sentence should earn its place; this single sentence barely does.

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 that there are zero parameters and an output schema exists, the description still needs to orient the agent about the output's nature. '摘要' (summary) is minimal. The agent is left guessing what fields the summary contains. For a simple tool, this is adequate but not complete.

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?

The input schema has zero properties and schema description coverage is 100%. For a parameterless tool, the baseline is 4. The description adds no parameter info because none exist, which is acceptable.

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 '最后一次活动 — 最近一次运动的摘要' which translates to 'last activity — summary of the most recent exercise'. It identifies the resource (last activity) and a verb (summary implied), but 'summary' is vague. Among many sibling tools like activity_detail, activities, and get_activity, it does not clearly differentiate its scope or level of detail.

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?

No usage context is provided. The description does not indicate when to prefer this tool over alternatives (e.g., for a quick overview vs. detailed breakdown). There is no mention of prerequisites, limitations, or when not to use it.

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