save_session_event

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

With no annotations, the description carries full burden. It discloses a write-through guarantee and content truncation to 2000 chars. It also notes that session_id comes from session_bootstrap(). It does not cover error handling or rate limits, but overall adequately discloses key behaviors.

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?

The description is relatively concise, with a front-loaded purpose and a bullet list of event types. The 'Stage 8' label adds minimal overhead. Every sentence serves a purpose, though the list of event types could be integrated more succinctly.

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 simple logging tool, the description is complete: it explains what, when, and how to use it, and specifies parameter constraints. The output schema is assumed to cover return values, so no further detail is needed.

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 0%, so description must compensate. It adds meaning by defining event types ('turn', 'tool_call', etc.), explaining that session_id is from session_bootstrap(), and noting content truncation. This provides valuable context beyond the bare schema.

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?

The description clearly states the tool's purpose: to persist an atomic event to session_events. It specifies the verb 'persist' and the resource 'session_events', and provides usage context ('call after every tool call'). However, it does not explicitly differentiate from sibling tools, though its logging function is distinct.

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?

The description gives explicit when-to-use guidance: 'Call this after every tool call, file write, and classification decision.' It lists event types, providing clear context. It does not mention when not to use or alternatives, but the instruction is straightforward.

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