Vibe Board VE

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

With no annotations provided, the description carries the full burden of behavioral disclosure and does so comprehensively. It explicitly documents the critical side effect ('any currently-active sessions on the same project are automatically marked 'abandoned' with ended_at=now'), explains the 'one active session per project' constraint, and details the return structure including handoff components and abandoned_sessions. This goes well beyond basic functional description.

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 efficiently structured with zero wasted sentences. It front-loads the core purpose, immediately follows with the critical side effect, provides usage guidance, details return components, and specifies the exact response structure - all in a compact paragraph where every sentence adds essential information.

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 mutation tool with no annotations and no output schema, the description provides exceptional completeness. It covers the tool's purpose, behavioral side effects, usage context, parameter context, and detailed return structure including all four response fields (session_id, abandoned_sessions, handoff, message) and handoff subcomponents. This fully compensates for the lack of structured output 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 100%, so the baseline is 3. The description adds value by explaining the purpose of the session_type parameter ('single agent', 'coordinated multi-agent', 'long-running async work') and the metadata parameter's storage behavior ('Stored on the session document verbatim'), which provides context beyond the schema's enum values and type definitions. However, it doesn't elaborate on project_id beyond what the schema already states.

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 with specific verbs ('Start a new work session', 'get the previous session's handoff') and distinguishes it from siblings like board_end_session (which ends sessions) and board_get_handoff (which retrieves handoff without starting a session). It explicitly identifies the resource (project) and scope (only one active session per project).

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 provides explicit usage guidance: 'Call this at the start of every substantive session so the next one can pick up where you left off.' It also distinguishes when to use this tool versus alternatives by explaining the side effect that automatically abandons other sessions, making it clear this is the primary session initiation tool rather than board_get_handoff or board_end_session.

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