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

Annotations already declare destructiveHint=true, idempotentHint=false and readOnlyHint=false, so the safety profile is covered. The description's one genuinely additive fact is that data is isolated per caller (数据按调用方隔离), which tells the agent scoping behavior it could not infer from annotations. It stops short of stating that 'clear'/'delete' are irreversible or what 'list' returns.

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 core sentence is front-loaded and dense — resource first, then the operation set, then the scoping rule. The embedded JSON example is somewhat redundant with the schema's examples block, but it is short and does illustrate a realistic call, so little is wasted.

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?

For a 5-parameter, multi-action tool with no output schema and no annotations explaining state changes, the description covers the what but not the results: an agent cannot tell what 'list' returns (fields, ordering, whether include_done affects output) or whether operations are recoverable. Given the destructiveHint=true annotation, the missing irreversibility note is a real gap.

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%, with every property including 'action' documented in the schema itself, so the baseline of 3 applies. The description adds nothing parameter-specific beyond repeating the action vocabulary and one example that duplicates the schema's own example. It does not clarify interactions such as requiring id for complete/delete or title for add.

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 pairs the resource (待办事项清单) with an explicit enumeration of every operation the tool performs (新增/查看/完成/删除/清空), so an agent knows exactly what capability it is getting. No sibling tool in the supplied list covers todos, so no disambiguation is needed.

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?

Usage is implied through the action list and the single example ('add' with a title), which shows the typical call shape. However, there is no explicit statement of when to choose 'complete' vs 'delete', when 'clear' is appropriate, or any preconditions/exclusions. With no competing sibling, the omission is tolerable but leaves guidance at the implied level.

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