list_reference_parameters

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

With no annotations, the description must carry the full behavioral burden. It does disclose that the output marks which parameters are in the free sample, which is useful context. However, it does not explicitly state that the operation is read-only, nor mention any rate limits, pagination, or error behavior. For a simple list operation, the read-only nature is implied, and the free-sample marking adds value, but more could be disclosed.

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, front-loaded sentence that directly states the action and resource. Every word earns its place; there is no fluff or repetition. It is appropriately sized for the tool's simplicity.

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?

Given the tool's low complexity (2 optional params, no output schema), the description covers the key aspects: what is listed, the free-sample marking, and the optional domain filter. It does not explicitly specify the return format (e.g., array of objects) but mentions keys, labels, and domains, which gives a reasonable idea. For a simple list tool, this is largely sufficient, though a bit more detail on return structure would round it out.

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 already provides 100% coverage for both parameters: domain has a description listing valid values, and tax_year has a description and enum. The description only repeats 'Optionally filter by domain' and 'for a tax year', adding no new meaning beyond the schema. Since coverage is full, the baseline of 3 applies, and the description does not enhance parameter understanding.

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 action (list), the resource (U.S. federal financial-planning parameters), and the scope (for a tax year). It specifies output content (keys, labels, domains) and the free-sample marker, which distinguishes it from sibling tools like get_reference_parameter (singular retrieval) and list_archetypes (different resource). This is a specific, unambiguous purpose.

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 usage for listing parameters with an optional domain filter, but it does not explicitly state when to prefer this over get_reference_parameter or other sibling tools. It provides no exclusions or alternative names. The context is implied by the verb 'list' versus 'get', but not made explicit, so guidance is only implicit.

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