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

No annotations are provided, so the description carries the full burden of explaining behavior. It does not disclose what the tool returns, whether it performs a comparison, what 'criteria and filters' refer to, or any side effects. The text is incoherent and provides no useful behavioral context.

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 definition is short, but brevity without clarity is under-specification, not conciseness. The single sentence is malformed and must be rewritten before it can be considered efficient or well-structured.

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 annotations, no output schema, and empty structured metadata, the description is the only source of context, and it provides almost none. An agent cannot tell what criteria are compared, what inputs it might accept, what the result means, or how it relates to the sibling tools.

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 input schema has zero properties, so there are no parameter semantics for the description to clarify. The baseline for 0-parameter tools is 4, and the description's vague mention of 'criteria and any filters' does not actively harm parameter understanding, though it adds no real meaning.

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 is grammatically broken and does not state a clear verb or resource: 'The criteria and any filters of the The covers a UK self build needs comparison.' It offers no concrete statement of what the tool does, and the title 'What is compared' is too vague to rescue it. It fails to distinguish compare_criteria from siblings like compare_options or compare_table.

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 guidance about when to use this tool versus compare_options, compare_table, or any other sibling. The description does not indicate any context, prerequisites, or exclusions, leaving the agent with no basis for selecting this tool.

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