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

Annotations already declare read-only and safe behavior. The description adds useful context beyond that: the feed is public, editorial, and returns paginated photo objects with URLs and metadata. It does not contradict annotations and provides insight into the return format and ordering options, though it omits details on how pagination is controlled.

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 a single sentence that front-loads the primary action ('Fetch'), specifies the resource, and lists key attributes (ordering, output type). Every word contributes to understanding, with no fluff or redundancy. It is appropriately concise.

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 simple list tool with strong annotations and an output schema, the description sufficiently covers the key behaviors and return type. However, it leaves gaps around pagination control and does not explicitly differentiate from sibling listing tools, so it is not fully complete for complex usage scenarios.

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 schema defines zero parameters (empty properties) despite examples showing page and per_page, creating ambiguity. The description mentions 'paginated' and ordering but does not explain how to specify the page, per_page count, or order (chronological vs popular). The baseline for zero params is 4, but the description fails to clarify the intended optional parameters, resulting in a lower score.

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 the tool fetches Unsplash's public editorial feed of recently curated photos with specific ordering options (chronological or popular) and describes the output. This distinguishes it from sibling tools like search_photos or user_photos by specifying the exact resource and scope.

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 implies use cases through 'editorial feed' and 'curated photos' but does not explicitly state when to prefer this over related tools like collection_photos or topic_photos. There are no exclusions or alternative recommendations, leaving the agent to infer the appropriate context.

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