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

Beyond the annotations (readOnly=false, idempotent=false, destructive=false), the description discloses the validation precondition (schema v1), the quota consumption rule and its non-refundable nature ('A Free account saves 3 designs in total, the editor's saves included (deleting one does not give a save back)'), the ownership/attribution semantics ('flagged as created by this key'), and what is returned. This is materially more than the structured fields convey.

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 in the first clause, and the quota caveat is appended rather than buried. Four sentences are justified by the amount of distinct information (validation, return values, routing, limits), though the parenthetical about deleted saves is dense enough that it could be tightened.

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?

There is no output schema, and the description compensates fully by naming the return payload (new design id and editorUrl) and explaining what that URL is. Combined with the validation precondition and quota limits, an agent has everything needed to call this correctly and act on the result.

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 100% so the baseline is 3, but the description adds an actionable constraint the schema does not: the design body must validate against schema v1, which points the agent at get_design_schema before calling. The `name` parameter's human-recognition intent is left entirely to 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 description states a specific verb and resource ('Save a design to the cloud') and immediately scopes it to the human-facing editor, which cleanly separates it from update_design (mutation of existing) and open_in_editor (opening, not creating). An agent can identify this as the creation entry point 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 clear routing guidance ('This is how agent work reaches a human: create it, then hand back editorUrl... or create_share_link for someone without an account') and names two relevant siblings with the condition that selects each. It never states the exclusion case, e.g. that an already-saved design should be modified with update_design rather than re-created, so the when-not half of the guidance is implicit.

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