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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and external-network behavior are covered. The description adds real value by disclosing the source hierarchy ('local bank, then Unsplash/Pexels'), which explains where results come from, but says nothing about result limits, caching, or failure behavior when no image matches.

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?

A single compact sentence with the resource and the most decision-relevant fact (verified URLs, source order) front-loaded. It is a fragment without a verb, which slightly weakens readability, but there is no wasted text.

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 usefully signals that results are URLs ready for use, and all five optional parameters are self-documenting via the schema. An agent has enough to invoke it correctly; only edge-case behavior (no results, provider outages) is unaddressed.

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% and each of the five parameters carries its own description, including enum semantics for category, provider, and orientation. The prose adds nothing beyond the schema, so the baseline 3 applies.

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 names the concrete resource ('Stock photos') and quality guarantee ('verified, ready-to-use URLs'), so an agent can tell it apart from find_video and find_icon without opening a schema. It is a noun phrase rather than a verb+resource statement, but the intent is 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?

There is no statement of when to reach for this tool versus find_video, find_icon, or upload_image, and no prerequisites or exclusions are given. The provider fallback order hints at sourcing behavior but is not framed as usage guidance.

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