Find free, licensed photos

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

Adds substantial behavior beyond readOnlyHint/openWorldHint: conditional provider selection driven by environment keys, result contents (licence, author, attribution line), and a default filter that removes photos likely showing other brands' logos. These are non-obvious operational traits an agent could not infer from annotations or 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?

Four front-loaded sentences covering purpose, sourcing, result shape and usage advice; the sourcing/provider detail is dense but each sentence carries distinct information. Minor editorial advice is the only borderline filler.

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 discloses result fields (licence, author, attribution), so return shape is covered. Pagination/count limits and orientation semantics remain unaddressed, a small gap for a 4-parameter tool.

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 only 25%, so the description must compensate — and it partially does by implying allowBrands ("removed by default") and the intent of query (scene description). However, count and orientation are undocumented in both places, leaving the compensation incomplete.

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 ("Search commercially usable photos for pages and posts") and the licensing scope, which no sibling tool touches. An agent can immediately tell this is an image-sourcing tool rather than a publishing or planning tool.

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 clear usage context: stock photos for mood and backgrounds, while the product should be the seller's own photo. It also explains provider fallback conditions (PEXELS_API_KEY / UNSPLASH_ACCESS_KEY set). No explicit when-not or sibling alternative is named, but there is no competing sibling to route to.

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