Filter options

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

Annotations already declare read-only, idempotent, non-destructive, open-world behavior, so the bar is lower. The description still adds real context beyond them: the lookup is backed by Divar's own typed search, and the result set varies by whether `query`/`brand` is supplied.

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?

Front-loads what the tool returns, then the with/without `query` branching in two compact sentences. Slightly dense with parentheticals but no filler.

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?

No output schema exists, and the description partially covers returns ('key, title, model count'), plus how to feed keys into dv_search. It does not describe pagination/limit behavior or error cases when a brand/category is unknown, but is otherwise sufficient for a read-only lookup tool.

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 100%, so the baseline is 3, but the description genuinely clarifies parameter interplay the schema states only per-field: `query` triggers typed search, omitting it returns the full list, and `brand` restricts to one brand's models. That coupling of query/brand/filter is the key semantic an agent needs.

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?

States a specific verb+resource: it returns allowed values for a filter (brand/model keys, districts, option lists), and gives concrete scale ('161 car brands'). It is clearly separable from dv_filters (which yields filter keys) and from dv_search (which consumes the keys).

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?

Explicitly explains the two modes: with `query` it uses Divar's typed search to map Persian text to a key, without it returns all brands or one brand's models, and it tells the agent to pass results into dv_search as brand_model/filters. It stops short of naming dv_filters as the sibling that supplies the `filter` key.

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