Create Crash Session

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

With no annotations, the description carries the full behavioral burden. It usefully discloses the automatic crash-marking behavior, but says nothing about idempotency (calling twice with the same sessionId), auth requirements, rate limits, or what the call returns — meaningful gaps for a write operation.

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?

Three tight sentences with zero waste: purpose first, then timing, then lifecycle behavior. Every sentence earns its place and the most important information is front-loaded.

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 low-complexity session-registration call with no output schema or annotations, the description covers purpose, timing, and post-hoc behavior adequately. It could be more complete by stating auth needs or return behavior, but nothing essential to invoking it correctly is missing.

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 description coverage is 100%, so all four parameters (userId, platform, sessionId, appVersion) are already documented in the schema. The description adds no format, constraint, or example detail beyond what the schema provides, so the baseline 3 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 specific verb+resource ('Registers a game session') and the goal ('for crash-free rate calculation'), so the agent knows exactly what the tool does. It does not explicitly contrast with the sibling horizon_create_crash_report, so the differentiation is left to inference rather than stated.

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?

Provides a clear when-to-use trigger ('Call this at app start') and clarifies the downstream lifecycle ('if the session later has a crash report, it is marked automatically'). It stops short of naming alternatives or exclusion conditions, but the timing guidance is unambiguous.

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