Next session card

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

Annotations declare readOnlyHint=false, destructiveHint=false, openWorldHint=false, and the description is consistent with that (it advances protocol state), adding the done=true termination signal and a protocol version marker. It still does not disclose what state changes on each call, why it is not read-only, or whether repeated calls are idempotent.

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?

A single front-loaded sentence with no filler; the type enumeration is compact and readable. The compression is slightly aggressive for a protocol tool, but nothing is wasted.

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 stateful protocol navigator with no output schema and 0% parameter documentation, the description should explain the session lifecycle, the card's fields, and the three inputs. It gestures at the loop but leaves an agent unable to call the tool correctly without external documentation.

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% for three parameters (note, advance, session_id), and the description mentions none of them. With no structured or textual explanation, an agent has no way to know what 'note' feeds into or what advance=false does versus the default true.

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 names the return artifact ('ONE next action card') and its possible shapes (host_cmd|mcp_tool|end), which is more specific than the title alone, but the operative verb is buried in jargon ('Session Protocol v1.2 navigator'). It does not differentiate itself from close siblings such as grok_agent_session_tick, session_begin, or session_end, leaving the agent to infer the boundary.

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?

'Host loops this until done=true' is real usage guidance: it tells the caller this is a polling-style call with a termination signal. However, it never says when to prefer this over session_tick or session_begin, nor what preconditions (e.g. an open session_id) must hold.

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