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

Beyond the annotations (readOnly/idempotent/non-destructive/openWorld), the description adds substantial behavior: login is required, the corpus excludes model-generated or third-party content, it does not constitute proof of accomplishments, recent corrections outrank older statements, and results are bounded. This is exactly the kind of context annotations cannot express.

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?

Front-loaded with the login requirement and the usage rule, then scope caveats. It is dense and clause-packed but nearly every clause carries distinct information; it stays within a few sentences with no filler.

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 steps in to characterize returns (only self-statements, recent corrections prioritized, old material possibly outdated, bounded result set). For a two-optional-param search tool whose annotations already cover safety, nothing material is missing.

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% and both parameters are already documented in the schema (query topic semantics, limit default 8 and its query-only applicability). The description largely restates this ('limit缺省8', blank-query behavior) rather than adding new syntax or format detail, so the 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+resource — retrieving the user's own past statements ('检索我自己说过的原话') — and sharply delimits scope with '只含自述，不含模型/他人内容', which distinguishes it from generic siblings like search_all or search_moments. An agent can tell what corpus this searches without opening the 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?

'问用户前先查本人原话' gives an explicit trigger condition, and the empty-vs-nonempty query branches ('空query读方向/约束/更正档案，有query按主题检索') tell the agent exactly how to invoke it. The closing caveat '结果有界，没命中不等于没说过' prevents a false-negative interpretation, which is real usage guidance.

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