session_open

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

No annotations are provided, so the description carries the full burden. It does disclose a genuinely important trait – that a per-session session_secret is emitted ONLY here, must be kept, and is required by sensitive verbs in strict mode – but omits session lifetime, idempotency on re-open, and any auth requirements.

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 dense sentence covers the action, the key return value, and the follow-up step with no filler. Slightly cryptic in phrasing ('ONLY here - keep it') but appropriately front-loaded and compact.

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-value structure need not be explained, and the description adds the one thing an agent must know that the schema cannot express: the session_secret's singular issuance and downstream requirement. Only session lifetime and error behavior are 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 description coverage is 100%, so the schema already documents agent_id, workspace_id, and metadata in detail. The description names the (agent_id, workspace_id) binding but adds no format or constraint detail beyond what the schema provides, so the baseline of 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?

States a specific verb (Open) and resource (a session), and specifies the binding scope: (agent_id, workspace_id). An agent can distinguish it from session_heartbeat and session_close, though it does not explicitly contrast with them by name.

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 trailing clause 'Heartbeat to receive broadcasts' implies a lifecycle (open, then heartbeat) but gives no explicit when-to-use, prerequisites, or exclusions relative to siblings like agent_register or workspace_resolve. Usage is inferable but not stated.

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