Wait for Session Activity

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds the key behavioral trait beyond them: this call blocks/waits for newer events rather than returning immediately. It does not say what happens when the timeout elapses (empty result vs. error), which is the one missing behavioral detail.

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 sentence whose first clause carries the core behavior and whose second clause routes to the alternative; nothing is wasted or buried.

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?

With annotations covering safety, full schema coverage on parameters, and an output schema handling return values, the description supplies the only thing structured fields can't: that this is a blocking wait vs. an immediate snapshot. Timeout-expiry behavior is left implicit but is inferable from the timeout_ms parameter.

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 cursor, max_events, session_id, and timeout_ms are already documented with their bounds. The description reinforces the cursor's meaning ('after a known cursor') but adds no new syntax or format detail beyond the schema, so the baseline 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 and resource ('Wait for Session activity events') scoped by a cursor, which is exactly what distinguishes it from the polling siblings. An agent can tell this apart from terminal_read_activity and terminal_read without reading either schema.

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?

Explicitly names the alternative (terminal_read_activity) and the condition that selects it ('without cursor for an immediate snapshot'), which is the inverse of this tool's cursor-based wait. When and when-not are both implied by that single contrast.

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