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

Annotations already cover read-only and idempotent hints, so the bar is lower. The description adds context about returning source metadata and exact UTC observation time, which is valuable. It also warns that source statements are not legal clearance, a non-obvious caveat. Lacks detail on rate limits or error handling but combined with annotations, this is above average.

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 sentences, each packed with unique value: action and scope, disambiguation from search, output characteristics, legal caveat, and alternative routing. No fluff, front-loaded with the core action. Exceptional efficiency.

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?

Given a single parameter, an output schema, and supportive annotations, the description covers most essential aspects. It clarifies the source limitation, the output nature, and the non-legal status. Minor gaps include typical error cases or what happens if the URL is unknown, but overall it's quite complete for its simplicity.

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 schema description coverage at 0%, the description must compensate. It defines 'sourceUrl' implicitly as the URL to retrieve, but doesn't specify format or constraints beyond the schema's maxLength. The description mentions 'known artwork URL', adding some meaning, but detailed semantics are limited. Baseline 3 is appropriate as the description provides minimal enrichment over 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 clearly states it retrieves a known artwork URL from specific museums and explicitly distinguishes it from search ('Not artwork search'). It names the resource (artwork record) and the supported sources, making its purpose unmistakable.

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 explicitly says when to use (known URL from The Met or Cleveland Museum of Art) and when not (not search, not legal clearance, use manual record input for other museums). This provides both positive and negative usage contexts, far above typical descriptions.

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