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

Annotations already establish mutation, non-destructive, non-idempotent, open-world behavior. The description adds useful operational detail: writes are asynchronous, so results are not immediately visible and clients must poll for confirmation. That is genuine beyond-annotation context, but it does not cover failure handling, ordering guarantees, or per-session limits.

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?

Three short sentences, each carrying distinct information: what it does, how batching relates to timing, and that writes are asynchronous. Front-loaded and free of filler, though the batching/timing clause is slightly compressed.

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?

The async-write caveat is important for a tool with no output schema, but the definition never says a drawing session must first be opened, nor does it describe what 'queued' means for ordering or conflict with other participants. Adequate for a 2-parameter tool, with clear gaps around prerequisites.

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 50%, so the description compensates by explaining that points are normalized 0..1 and must be composed against the current viewport before calling — meaning the schema's coordinate contract does not supply. It still leaves the 's' discriminator field and batching limits unexplained.

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?

Uses a specific verb and resource: 'Submit a normalized collaborative stroke' plus the mechanism ('real encrypted drawing controller'). It is clearly distinguishable from chat_send and drawing_history_export, though it does not explicitly contrast itself with drawing_open or drawing_close.

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 reference to a 'collaborative stroke' and the 'batch of points' implies use during an active drawing session, and mention of 'elapsed time' hints at latency sensitivity. However, no explicit when-to-use/when-not guidance is given, no prerequisite (e.g. an open drawing session) is stated, and no alternative sibling is named.

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