Search Api Facet List

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

With no annotations, the description carries the full disclosure burden. It does add real value by explaining that index_id is ignored and that filter[index] returned a 400, but it says nothing about pagination behavior, the 50-item default, or whether the call is a safe read.

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?

Purpose is correctly front-loaded, but the second sentence rambles through a nested em-dash explanation and an inline quoted error before restating the same point twice ('no field to filter on', 'there is no field to filter on instead'). It could be tightened considerably.

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?

An output schema exists, so return-value documentation is not required; the description still adds the important detail that each returned facet carries facet_source_id. The main gap is the unexplained page_limit parameter.

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 coverage is 0%, so the description must compensate. It thoroughly explains index_id (deprecated/ignored), which is exactly the kind of meaning the schema lacks, but page_limit is entirely unexplained despite being the remaining parameter.

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?

Opens with a specific verb and resource ('List Search API facets'), so the operation is unambiguous. It distinguishes itself from create-style siblings (search_api_facet_create) by being a read/list operation, though it never names siblings directly.

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 note that 'index_id' is no longer applied is genuinely useful usage context (it tells the caller not to bother filtering by index), but the description never states when to choose this tool over alternatives or what the intended calling context is.

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