Create drawing

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

Annotations declare readOnlyHint=false, destructiveHint=false and idempotentHint=false, so the write/repeatability profile is already known; the description adds meaningful behavior beyond that — the hard 500-element cap, that classDef/class are silently ignored, that non-flowchart Mermaid types are rejected, and that the response is a link. It does not mention permissions or what happens on failure.

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?

It is front-loaded with purpose and return value, then breaks into labeled blocks (Elements, Mermaid, Colors) that each carry non-redundant information. It is dense and runs long, but no sentence is filler; the color list is borderline padding but serves a real aesthetic purpose.

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 tool with a nested oneOf schema, six parameters and no output schema, the description covers the schema's hard edges (auto-layout vs manual coordinates, element vs Mermaid mixing, limits, ignored Mermaid directives) and states the return value. An agent has everything needed to compose a valid call.

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?

With 67% schema coverage the description must carry weight, and it does for the hardest part: element types, connector 'from'/'to' vs 'start'/'end', automatic sizing and label wrapping, palette suggestions, and direction semantics. The plain parameters (name, space, folderId) get no description-level elaboration, though folderId and space are already documented in the schema.

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 states a specific verb and resource ('Creates a NEW drawing from simple elements and/or a Mermaid flowchart') plus the return value ('returns its link'), and immediately scopes it against mutation of existing drawings. The agent can tell this apart from read_drawing and move_drawing without opening any 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?

It gives concrete selection guidance: prefer auto-layout and only supply x/y for grids or timelines, and elements and Mermaid may be combined in one call. What's missing is any explicit routing to siblings, such as using list_folders before folderId (that only appears in the schema) or which tool to use to edit an existing drawing.

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