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

Annotations only declare readOnlyHint=false, so the description carries most of the burden and does add real context: data is isolated per caller, a 'list' partition exists with default 'default', and IDs are visible in list results. It leaves the destructive side thin – it never says that delete/clear are irreversible or that clear removes only completed items.

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?

Three short clauses: what it does, when to use it, and a canonical example. Front-loaded with the operation list and zero filler; 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?

With no output schema the description should hint at returns, and it does partially by saying IDs appear in list results. Given 100% schema coverage and a clear action enum, the only real hole is the irreversibility/permission profile of delete and clear, which the minimal annotations do not cover either.

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 schema already documents every field and the enum; the baseline would be 3. The description goes beyond it by supplying a worked example ('{"action":"add","title":"周五前提交周报"}') that shows how action and title combine, and by explaining the caller-isolation semantics of the list parameter.

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 ('管理待办事项清单') and enumerates all five supported operations (新增/查看/完成/删除/清空), so there is no ambiguity about what the tool does. None of the sibling tools (weather, currency, IP, time) overlap, so differentiation comes for free.

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?

It gives concrete trigger phrases ('记个待办/我还有哪些事/把某条标记完成') that map natural user intent onto this tool, which is exactly the guidance an agent needs. It does not state when NOT to use it or how to pick between the five actions beyond the enum, which keeps it just short of a 5.

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