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

Annotations already cover readOnlyHint, idempotentHint, and destructiveHint=false, so 'Read-only' repeats structured data. However, the description adds genuinely new behavioral context: no auth required, cheap to call, and concrete per-IP rate limits (10 uploads/hour, 500 views/hour) that an agent cannot infer from annotations or the empty schema.

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?

Two sentences, zero filler, front-loaded with what is returned before the routing guidance. Every clause carries information.

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?

With no output schema, the description compensates by enumerating the returned fields (version, endpoints, features, rate limits). Combined with the usage routing, an agent has everything needed to decide and call correctly.

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?

The tool takes zero parameters, which is the baseline-4 case per the rubric. The description correctly implies a no-argument call and adds no misleading parameter guidance, though there is nothing further it could meaningfully say.

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?

States a specific verb and resource ('Return Oh My Share service metadata') and enumerates exactly what metadata: version, REST/MCP endpoints, feature list, and rate limits. The scope is unambiguous and clearly distinct from the sibling content tools.

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?

Gives explicit timing ('use it once at startup to discover capabilities') and names the alternatives for the other case ('use list_assets or search_gallery for actual content'). Nothing about when-to-use or when-not-to-use is left to inference.

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