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

Annotations already declare non-read-only, non-destructive, non-idempotent, open-world behavior. The description adds one genuinely useful behavioral fact beyond that: applied strokes are preserved rather than cleared. The remaining sentences are prompt-injection boilerplate that restate the same warning twice and disclose nothing about the tool's own effects.

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?

Only the first sentence does tool-specific work; the second and third are near-duplicate untrusted-data warnings that pad the definition. The useful content is front-loaded, but roughly half the text is repetition that dilutes the signal.

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 state-transition tool with a nested object parameter and no output schema, the definition leaves key questions unanswered: what happens to the session afterward, whether the drawing must be open first, and whether the call can fail. It also does not differentiate parameters, so it is not complete enough on its own.

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 coverage is only 50%, so the description is expected to compensate, and it says nothing about either the 'session' or nested 'input.roomId' arguments. An agent must rely entirely on the schema to learn that session names an ephemeral encrypted participant session and roomId is a canonical fort flag.

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 state transition: 'Return from collaborative drawing to conversation.' That is enough to distinguish it from drawing_open and the room/session family without opening a schema. It stops short of naming the sibling it mirrors, so it is clear but not fully differentiated.

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 phrase 'Return from collaborative drawing to conversation' implies the context (you are in a drawing and want to go back), which is useful implicit guidance. However, there is no explicit statement of when to call this versus drawing_open or session_close, and no stated preconditions such as requiring an active drawing session.

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