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

Annotations already declare readOnlyHint and idempotentHint, so safety is covered. The description adds genuinely new behavioral context beyond them: the input must be the verdict object returned by the bazi 用神 decision step, and the ji five-elements are deliberately excluded from the produced pool. It does not discuss pool size, ordering, or failure behavior when status is 'partial'.

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?

One dense but front-loaded paragraph: purpose first, then parameter meaning, then the deliberate exclusion, then hand-off to sibling tools. No filler sentences, though the semicolon-chained clauses require careful reading and could be split for scanability.

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 an output schema present, the description need not enumerate return values, and it covers input provenance, the ji exclusion, and pipeline position. What remains unstated is behavior on partial verdicts and any guidance on pool adequacy, which a caller choosing this tool would still want.

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 baseline is 3. The description still adds meaning beyond the schema by explaining that selected_yongshen is passed through directly from the 八字用神裁决 return (provenance/source tool), which the schema does not say, and by framing first_role/second_role as character-position roles with omission meaning a single-character name.

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: generate a character pool (字池) by yong/xi five-element role. It immediately names the two downstream siblings it is not (naming_compose, naming_character), so an agent can place it in the naming pipeline 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?

Gives clear sequencing guidance: use naming_character to look up single-character facts before combining, and naming_compose to combine candidates after the pool exists. It also states the generation-stage exclusion ('不提供 ji 字池'). It does not state explicit preconditions such as requiring a resolved 用神 from bazi_yongshen beyond the parameter note, so it falls short of full when/when-not coverage.

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