start_game

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

With no annotations, the description carries the full disclosure burden, and it does add two real traits: the window is created lazily (nothing opens until called) and the call is idempotent ("safe to call again; it won't open a second window"). It says nothing about startup latency, failure modes, or whether calling it resets existing game state — meaningful gaps for a no-annotation tool.

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-loaded with the action, followed by the dependency note and the safety note; three short clauses that each add something. The clause "Nothing opens until you call this, so opening the app spawns no windows" restates the same point twice, which is minor padding.

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?

An output schema exists and parameters are empty, so the description only needs to cover behavior and sequencing, which it mostly does. What is missing — startup timing, failure behavior, interaction with any prior session state — is small but not zero for a session-lifecycle 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?

The tool takes zero parameters, so there is nothing for the description to disambiguate beyond what the empty schema already conveys. Baseline 4 applies.

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 concrete effect: it brings up the game window, and clarifies that the app itself spawns no windows until this is called. "Summon" is slightly whimsical, but the following clauses pin down the resource and the effect. It doesn't explicitly contrast with close_game, though the "ready to play" → "take a screenshot" sequencing implicitly routes to get_screenshot.

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 a clear trigger ("call this when you're ready to play") and a follow-on action ("then take a screenshot"), which orients the agent in the workflow. There is no real alternative tool to exclude, so the absence of when-not guidance is minor. It does not say what to do on failure or how long startup takes.

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