Shop prices of a phone

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

Annotations already declare readOnly/idempotent/non-destructive, so the description's job is to add context, and it does: prices are in Toman, the result is sorted cheapest-first, per-shop notes explain price differences, and shops are advertisers the site does not vouch for — a meaningful trust caveat. It omits any statement about result caps or what happens when no shop currently lists the product.

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?

Three tight sentences that front-load the outcome, then the caveat that makes the numbers interpretable, then the trust warning. Every sentence earns its place; the only weakness is the slightly awkward mid-sentence break around 'read the note. Cheapest first.'

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?

With no output schema, the description usefully compensates by naming the returned fields and the sort order, and annotations cover the safety profile. It is nearly complete for a simple read-only list tool, missing only edge-case behavior (empty results, stale vs. current pricing beyond the include_old flag).

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%, with `id` even pointing at the sibling tools that produce it and `include_old` fully explained, so the baseline is 3. The description adds no parameter-level meaning of its own and never mentions include_old or how expired prices affect the cheapest-first ordering.

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 and resource — listing per-shop current prices for a given phone on Mobile.ir — and enumerates the returned fields (price in Toman, shop, city, note, warranty). It does not explicitly contrast itself with the closest siblings (mi_market_prices, mi_price_history), so an agent must infer the distinction from the name alone.

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?

Implied usage is clear (you want shop-by-shop offers for a known product id) and it adds a reading instruction ('read the note') plus an ordering guarantee ('Cheapest first'). However, it never says when to prefer this over mi_market_prices or mi_price_history, and there are no explicit exclusions.

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