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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered before reading the description. The description's added value is the output shape (coding, name, domain, key-point count), which matters because no output schema exists, but it says nothing about result size, ordering, or what an empty stage filter 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 scope and the get_standard routing hint are front-loaded in the first two clauses, with no filler. The trailing English sentence "List a subject's standards." largely duplicates the Chinese text and adds little for a reader who already parsed the first sentence.

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 simple two-parameter read tool with a fully described schema and full annotation coverage, the definition covers purpose, routing, optional filter, and returned fields — enough to call it correctly. Only ordering, volume, and empty-result behavior remain unaddressed, which are minor for a listing tool.

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 carry their own descriptions including an example for subject, so the schema already does the heavy lifting. The description adds only that stage is an optional narrowing filter ("可限定一个学段"), which matches the baseline-3 case where the schema leads.

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 and resource (list a subject's standards), names the optional scope (stage), and enumerates the returned fields (编码、名称、领域、要点条数). It also explicitly separates itself from get_standard, so an agent can pick between the overview and detail tools without opening a 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?

"适合先看全貌再用 get_standard 看细节" gives a concrete when-to-use rule and names the alternative tool, which is exactly the routing decision an agent faces here. It stops short of exclusions — it does not say when to prefer search_standards or list_subjects instead.

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