Search SIM card numbers

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

The annotations already declare read-only, idempotent, non-destructive, open-world behavior, so the description only needs to add context. It does: it discloses that seller names and phone numbers are absent from results and that contact happens outside the tool via `url`, which is exactly the kind of privacy/return-shape fact annotations cannot convey.

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?

Two short paragraphs, front-loaded with the resource and destination site before the filter list. The second paragraph packs several unrelated facts (filters, contact rules, number format) into one block without bullets, but no sentence is padding.

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 14-parameter, no-output-schema search tool with strong annotations, the description covers the essentials: what is searched, what can be filtered, and what is deliberately withheld from results. Pagination and price-sorting edge cases live in the schema, and with no output schema present the absence of a fuller return-value description is a minor gap rather than a blocking one.

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; every one of the 14 parameters is already documented, including the operator ranges and the `prefix` overrides `operator` rule. The description's filter recap adds only the 'endswith 1111' framing, and its line that '`number` is the full 11-digit number as sold' is ambiguous against the schema's `number` parameter (the 7-digit subscriber part), which could mislead rather than clarify.

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 states a specific verb and resource — searching SIM card numbers listed for sale on Mobile.ir — and names the domain (Iran's numbered-SIM market) and the fields carried (operator, number, price). It does not differentiate itself from siblings such as mi_sim_summary or mi_used_search, so an agent must infer the split between listing search and summary.

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 second paragraph gives clear operating context: which facets can be filtered, that seller identities are withheld, and that `url` must be opened on the site to make contact. It stops short of explicit when-not or alternative-tool routing (e.g. when to use mi_sim_summary instead), so it lands just under the top band.

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