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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, and the description adds essentially nothing new – 'Unsplash' merely restates the open-world external source. It says nothing about rate limits, result counts, pagination, or whether results are cached/attributed.

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 words, front-loaded, zero waste. Its brevity is efficient, though it borders on under-specification handled in other dimensions.

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 2-parameter tool with no output schema and an undocumented required query, the description should at least state what query accepts and roughly what comes back. It leaves the agent to guess both.

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 required 'query' parameter is completely undocumented in both schema and description, leaving only 50% coverage overall. The description does not explain whether the query is free text, keywords, or identifiers, so it fails to compensate for the schema gap.

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 concrete verb (Search) and resource (stock photos) plus the provider (Unsplash), which lets an agent separate it from search_icons, search_videos, and generate_image. It stops short of describing search scope or result type, so it is clear but not richly differentiated.

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 when-to-use or when-not-to-use guidance and no naming of alternatives such as search_icons or generate_image. Usage is only implied by the word 'Search'.

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