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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation and destructive nature are known. The description goes beyond by explaining the two possible outcomes (immediate execution vs proposal) and the need to inspect the response status field. It also warns that deletion is disabled by default and requires organizer authorization. This adds meaningful behavioral context beyond what annotations provide.

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?

Two sentences with no filler: the first states the core destructive action, the second covers the two most important decision-relevant facts (allowed by default? immediate vs proposal, and how to know). Every clause earns its place.

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 destructive tool with full schema coverage, the description explains the precondition (organizer enablement), the async branch (proposal vs immediate), and how to interpret the outcome status field. It doesn't explicitly explain return values or error cases like non-existent session, but with no output schema defined and a clear schema, the description carries the essential burden. The only minor gap is what specific status values may appear.

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 fully documents all parameters including org precondition, eventId source, and request_id idempotency semantics. The description adds no new parameter-level information beyond the schema, but doesn't need to because the schema already explains the purpose of each parameter clearly.

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 states a specific verb and resource: 'Permanently delete a session.' It clearly distinguishes this from sibling tools like update_session or create_session, and from less destructive operations. The addition of 'permanently' signals severity unambiguously.

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 explicitly states when this tool is available: only when an organizer has enabled direct destructive access. It also explains that the operation may execute immediately or file a proposal depending on org settings, and directs the agent to check the response status field to tell which occurred. This gives clear context for when and how to use it, and implicitly warns against assuming immediate effect.

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