snapshot

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

With no annotations, the description carries the behavioral burden well: it discloses that output can be large, supports incremental retrieval via seq, has special behavior for ack and simplify, and can be reduced to header fields for polling clients. It does not discuss permissions or sensitivity, but the core behavioral traits are covered.

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 dense but front-loaded with what the tool returns, then immediately covers size, filtering, incremental retrieval, and UI-client patterns. Every sentence is relevant, though the paragraph is long and somewhat run-on.

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?

Given eight optional parameters, an output schema, and no annotations, the description provides enough context to call the tool correctly: it explains content scope, output size risk, filtering strategies, incremental updates, and polling-client behavior. No critical agent-facing information appears 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 coverage is 100%, so the baseline is 3, but the description adds meaningful usage semantics beyond the schema: how to keep results small, how server_id and seq feed into since, and how ack/simplify are intended for UI polling clients. It does not explain every parameter individually, but it adds practical interpretation.

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 that this returns a full conversation snapshot for open sessions, including prompts, replies, thinking, tool calls, plans, approvals, and related state. It is specific about the resource and contents, but does not explicitly differentiate itself from most sibling tools; the reference to 'item' is the only routing signal.

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 usage guidance: pass session to narrow scope, use last/types/exclude_types to keep results small, use since with server_id and seq for incremental changes, ack for notification-relaying UI clients, and simplify plus item for polling UI clients. It names the alternative, item, for retrieving one full item.

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