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

Annotations already indicate readOnlyHint=false and destructiveHint=false, so no contradiction. The description adds that it saves specific categories of data, but doesn't disclose side effects like overwriting existing snapshots or persistence behavior beyond what schema parameters imply.

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?

Two short sentences deliver the core purpose and usage timing without any filler. The structure is front-loaded with the action, then the when-to-use guidance.

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?

The tool has 9 optional parameters, a full output schema, and schema descriptions cover all parameters. The description explains what the snapshot contains and when to invoke it, which is adequate. It could mention the restore counterpart, but that's not essential.

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?

All 9 parameters have comprehensive descriptions in the schema, covering scope, bucket, state_key, session_id, TTL, etc. The tool description adds no additional parameter semantics, so 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?

The description clearly states 'Save active state, recent events, TODOs, and pending decisions for restart' with a specific verb and resource. It distinguishes itself from sibling tools like restore_restart_snapshot by focusing on the creation aspect.

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 explicitly says 'Call this before handoff or when context may be lost,' providing clear timing guidance. It doesn't mention exclusions or alternatives, but the context is sufficient for most use cases.

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