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

Annotations already declare readOnlyHint=false, openWorldHint=true, destructiveHint=false. The description goes well beyond them: recordings are preserved, the session is removed from both Planner and project folder, cancellation is recoverable only by re-scheduling, confirmation defaults on but can be disabled, and the call reaches other people. The only soft spot is tension with destructiveHint=false, since removal is framed dramatically — but the explicit restore path largely justifies the non-destructive flag, so no contradiction.

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?

Purpose is front-loaded, but the text repeats itself: 'Recordings already made are kept' and 'Recordings that were already made stay in your account' say the same thing, and the removal from Planner/project folder is stated twice. Roughly half the sentences are redundant, which dilutes rather than reinforces the message.

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 one-parameter cancellation tool with no output schema, the description covers side effects, reversibility, authorization, and human-confirmation requirements well. It could still mention error behavior (e.g., cancelling a non-existent session) or confirmation of what the response returns, but nothing critical is 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?

There is a single required parameter with 100% schema description coverage ('Session ID from list_sessions'), so the schema already carries the semantics. The description adds nothing about session_id, making the baseline 3 correct.

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 first sentence gives a specific verb and resource: 'Remove a scheduled session from the Planner,' which cleanly separates it from riverside_schedule_session, riverside_update_session, and riverside_list_sessions. It stops short of naming an alternative, and the repeated restatements of the same action slightly blur an otherwise sharp purpose.

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?

Usage is implied by the verb (cancel a session you no longer want), and the description adds real operational constraints — human confirmation required, API key must have app access. However it never says when to cancel versus reschedule or update the session instead, so the agent must infer the selection rule.

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