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diff_game_versions

Idempotent

Compare two War Selection snapshots to see changed files, unit types, build rules, researches, auras, overrides, and API signatures. Writes full diff to diffs/.

Instructions

Structured diff between two snapshots (default: previous vs latest; a/b accept a snapshot id, id prefix or engine version). Sections: changed files, unit types (legacyIds), build rules (cost, health, ...), researches and upgrades, auras, unit overrides, API index added/removed/changed signatures. Takes a new snapshot first if the game changed. With a single snapshot it explains that the next update produces the diff. The full diff is written to the data folder (diffs/).

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
aNo
bNo
limitNo

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.4.0

TDQS

A3.9/5.0
Behavior4/5

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

Annotations mark readOnlyHint=false and idempotentHint=true; the description adds real behavioral context that explains those flags: it takes a new snapshot first if the game changed, and it writes the full diff to the data folder (diffs/). That is a genuine side effect disclosure beyond the annotations, though failure modes are not covered.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loads the core purpose, then the accepted parameter forms, then the side effects. Dense but every clause carries information; only the parenthetical section enumeration is slightly list-heavy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description supplies the return shape (the section list) and where the artifact lands, plus the snapshot side effect and the single-snapshot explanation. The unexplained limit parameter and lack of error/edge behavior keep it from being fully complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must carry all parameter meaning. It does well for a/b (snapshot id, id prefix, engine version; default previous vs latest) but the third parameter, limit (default 100), is never explained, leaving a third of the surface undocumented.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (structured diff) and resource (two game version snapshots) and enumerates the diffed sections (files, unit types, build rules, researches, auras, overrides, API index), which is far more than a tautology. It does not explicitly differentiate itself from the sibling diff_mod, so it stops short of a 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explains the default behavior (previous vs latest) and the accepted forms for a/b (snapshot id, id prefix, engine version), plus the single-snapshot edge case. It never names the alternative diff_mod as the choice for mod-vs-mod comparison, so the when-not-to-use side is missing.

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