Open a group of CLI seats

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

Annotations only declare it is non-readonly, non-destructive, non-idempotent and closed-world. The description goes well beyond that by disclosing the in-memory lifecycle ('Nothing is saved'), that each seat retains its own native session across rounds, and that host exclusions do not apply to seats — all behavior an agent could not derive from structured fields. It stops short of covering failure modes or cleanup semantics, so not a 5.

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 short sentences, front-loaded with the core action and scope, then the persistence caveat, then seat behavior. No filler. Minor density issue in 'native tools and permissions, the given cwd, explicit options', which is terse to the point of ambiguity.

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?

An output schema exists, so return values (presumably a group handle) need no explanation here. Given the tool's moderate complexity, the description covers the essential mental model — ephemeral grouping, seat count, per-seat session persistence. It omits what happens if a seat id collides or how a group is closed, which a mutation-style tool could reasonably state.

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 only 50%, so the description has to compensate. It does partially: 'the given cwd' and 'explicit options' map to the cwd/provider_options fields, and '2–6 CLI seats' restates the array bounds. But the seat 'id' pattern and provider enumeration get no added meaning, leaving the low-coverage half only loosely covered.

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 and resource with scope baked in: 'Create an in-memory group of 2–6 CLI seats for collaborative rounds.' An agent can tell this is a grouped-seat primitive distinct from a single-agent start. It does not, however, name any sibling (e.g. start_agent or run_round) to anchor the contrast, so it falls short of the top tier.

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?

'For collaborative rounds' implies the use case, and 'Nothing is saved' signals a session-style tool rather than a persisted one. But there is no explicit when-to-use rule, no when-not condition, and no pointer to alternatives such as start_agent for a single seat. Usage is left to inference.

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