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

There are no annotations, so the description carries the full burden of behavioral disclosure. It describes the data content and optional filtering but never explicitly states that the tool is a read-only lookup, what the output format is, or what happens with invalid filters.

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 concise sentence with the resource front-loaded and the optional filtering included. The parenthetical list of fields makes it slightly dense, but overall it is efficiently worded.

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 optional-filter lookup with no output schema, the description conveys the domain, the fields of the options, and the filtering capability. However, it is incomplete on filter parameter semantics and does not explain the context for choosing this tool over 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?

Schema description coverage is 0%, so the description must explain filterKey and filterValue. It only mentions 'optionally filtered by a tag value,' which hints that filterValue is a tag value but leaves filterKey's role undefined and provides no valid values or key names.

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 names a specific resource ('options in the UK motor trade insurance') and lists the fields returned, but it lacks an explicit verb such as 'list' or 'retrieve.' It also does not clearly differentiate itself from siblings like compare_criteria 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?

No guidance is provided about when to use this tool versus its siblings. The phrase 'optionally filtered by a tag value' implies one usage mode, but there are no explicit conditions, exclusions, or references to alternative tools.

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