analyze_contrast

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

With no annotations, the description supplies some behavior: the tool reads the current region rather than taking parameters, and it is a read-only analysis rather than a mutation. However, it does not explain how foreground/background are determined, what the result looks like, or what happens if no region is selected.

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?

Three short sentences present purpose, prerequisite, and use case with no filler. The core action 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 parameterless tool, the invocation requirement is covered, but with no output schema the description should state what the tool returns or displays. The ambiguity of how foreground and background are distinguished also remains unaddressed, leaving the agent with partial context.

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?

There are zero parameters and 100% schema coverage, so the schema leaves nothing undocumented. The description adds useful stateful context by requiring a prior region selection, which is more than the empty schema conveys.

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 identifies the operation (analyze contrast) and the resource (foreground/background audio), and adds a WCAG accessibility use case that helps set it apart from sibling analyze_* tools. It does not explicitly contrast itself with any sibling, so it falls short of full 5.

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?

It gives a clear context ('checking accessibility compliance (WCAG)') and an explicit prerequisite ('Select a region first'). It does not mention when not to use it or name a preferred alternative, so no 5.

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