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

Annotations already establish readOnly, non-destructive behavior. The description adds useful context beyond that: no auth is required and the data comes from commons.wikimedia.org via the MediaWiki Action API. It does not mention rate limits or non-deterministic repeat-call behavior, but the core safety profile is well covered.

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?

The description is three purposeful sentences: what it returns, when to use it, and where it comes from. There is no fluff or redundant restating of the tool name, and the core purpose is front-loaded.

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 single-parameter, read-only tool with an output schema, this description is complete: it covers purpose, return fields, use cases, data source, and auth. Nothing required to invoke or select the tool correctly is missing.

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 only parameter, 'count', is fully documented in the schema with range and default, so the description does not need to repeat it. The description adds little parameter-specific meaning beyond framing the result as a 'random sample,' keeping this at the schema-covered baseline.

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 opens with a specific verb and resource: 'Get a random sample of Wikimedia Commons media files.' It also names the return shape (titles, page IDs, description-page URLs), which clearly distinguishes it from sibling search, category, and info 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?

The description gives clear use cases: 'discovery, sampling, or surprise me style prompts.' It does not explicitly name sibling alternatives or state when not to use it, so it stops short of full alternative-routing guidance.

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