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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, and the description clears it by disclosing two behaviors annotations cannot: the response distinguishes original curriculum text from kebiao-composed text, and a legacy 2022 code does not fail but reports which new standard absorbed it. It stops short of stating what happens for an unrecognized code.

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 content is front-loaded — resource, then return payload, then accepted code forms — and every clause earns its place. The cost is a single dense run-on sentence duplicated verbatim in a second language, which is useful for mixed-language agents but doubles the length without new information.

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?

There is no output schema, so the description carries the return-shape burden and does so by naming all four payload components including provenance marking and page numbers. For a one-parameter read tool this is close to complete; only the failure behavior for an unknown or malformed code is unaddressed.

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?

With one parameter at 100% schema coverage the baseline is 3, and the description does add value over the schema's bare "标准、要点或旧编码" by giving concrete examples of each code family. However, it still does not specify the code grammar or whether lookups are exact-match only, so the added meaning is illustrative rather than operative.

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 ("按编码查看一条课标" / "Look up one standard by code") and enumerates exactly what is returned: the standard sentence with provenance, all point originals with page numbers, academic requirements, and links. The accepted code formats (MA-S2-NA-02, point codes like MA-S2-NA-02.1, legacy MA-D2-AL-005) make it immediately distinguishable from list_standards and search_standards.

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?

"按编码查看" establishes the precondition that the agent already has a code, which implicitly separates this from the search/list siblings that produce codes. It does not explicitly say "use search_standards when you don't have a code" or name any sibling, so the routing is implied rather than stated.

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