Check a build at a character level

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

Annotations only declare readOnlyHint=true, so the description usefully adds behavior the schema doesn't: missing connecting passives are auto-filled and counted, Giant's Blood tripling is applied to weapon requirements, and the check mirrors export_build's enforcement rules. It stops short of describing what the pass/fail result looks like or how violations are surfaced, which matters since there is no output schema.

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-loads the purpose, then uses the remaining sentences for actionable instructions (leveling-phase cadence, sibling routing). It is dense with enumerated check categories but nearly every clause maps to a distinct behavior, 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 9-parameter nested tool with no output schema, the description covers the check domains, a behavioral gotcha (auto-filled passives), and where to go for other needs. The main gap is that it never describes the shape or nature of the check results, which is the one thing an agent must guess.

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 56%, so the description has to compensate, and it does for several params: it tells the agent to supply `weapons` and why (attribute requirements with Giant's Blood tripling), and clarifies how passives interact with '+5 to any Attribute' allocation. It leaves ascendancy/ascendancyPassives and gearAttributes largely to the schema, but adds real value beyond the structured fields.

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 ('rule-based checks') and resource ('a planned build at a given character level') and then enumerates the actual check categories (skill usability, gem/weapon attribute requirements, Spirit, passive budget, skill/support rules). This clearly separates it from evaluate_build, which is named as the different tool.

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 explicit invocation guidance ('Run it for each leveling phase (e.g. levels 12, 28, 45, 65, 90)') and routes the agent to the alternative for a different need ('For damage and survival numbers use evaluate_build'). It also ties scope to a sibling by noting these are 'the same rules export_build enforces'.

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