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

Annotations already declare readOnly/idempotent/non-destructive and open-world, so safety is covered. The description adds genuinely useful non-schema context: values are Rial per milligram (x100 = Toman per gram), timestamps are Tehran time, and points are thinned evenly. It stops short of describing the exact response shape (aggregate stats vs. array of points), which keeps it from a 5.

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 tight paragraphs, with the main action and output fields front-loaded and the units caveat parenthesized efficiently. Slightly compressed syntax ('Prices are Rial per milligram...') requires a re-read but no sentence is wasted.

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 tells the agent the returned fields (high, low, change) and the unit/timezone conventions needed to interpret them. The one remaining gap is the response structure — whether points come back as a series or as summary stats — which an agent must discover by calling.

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 description coverage is 100%, so both parameters are already fully documented including the period windows and the 2-50 points range. The description only restates day/week/month and that points are thinned evenly, adding no format or interpretation detail beyond the schema. Baseline 3 applies.

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 ('Get the Milli.gold 18k gold price series') plus the granularity options (day/week/month) and what the payload contains (high, low, change). It is clearly distinguishable from gold_prices, which is named for today's cross-platform price.

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 routes the agent: 'For today's price on every platform use gold_prices.' That names the alternative and the condition selecting it, while the period parameter covers the remaining usage choice. Nothing is left to inference about when to pick this tool.

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

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

Annotations already establish read-only, idempotent, non-destructive, open-world behavior, so the bar is lower. The description adds genuinely useful context beyond them: figures are rounded company-published totals and weights are in kilograms, which warns the agent not to treat values as exact or unit-ambiguous.

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 sentences, front-loaded with what is returned, then the caveat and the alternative. No filler and nothing buried.

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 no-parameter read-only stats tool with rich annotations and no output schema, the description covers content, precision caveats, and units. The only gap is not distinguishing itself from gold_milli_history, which shares the same domain.

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?

Zero parameters, so the baseline is 4; there is nothing schema-side to compensate for. The unit note (kilograms) is about returned values rather than inputs, but it is the only semantic clarification available for a no-arg tool.

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?

Specific verb ('Get') plus a precisely enumerated resource: users, trades, gold traded, gold held and branches. It also explicitly disambiguates from the sibling gold_prices, so an agent can pick correctly without opening either schema.

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 routes price lookups to gold_prices, which is the most likely confusion given the sibling set. It stops short of mentioning gold_milli_history, so the boundary for time-series/trend data is left for the agent to infer.

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

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

The annotations already declare this as a read-only, idempotent, non-destructive open-world operation. The description adds substantial behavioral detail beyond that: buy and sell price meaning, cheapest-first sorting, best_to_buy and best_to_sell fields, partial results when a platform fails, and the exclusion of platform fees.

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 front-loaded with the core purpose and then compactly covers output semantics, failure behavior, fee caveat, and sibling routing. Every sentence carries useful information and there is 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?

With no input parameters and no output schema, the description needs to carry the return-value burden, and it does: it explains buy/sell fields, row sorting, best_to_buy and best_to_sell, failed platforms, and fee exclusion. An agent has enough context to call and interpret the tool correctly.

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 tool has zero input parameters, so the baseline is 4. There are no parameter semantics to clarify; the description instead documents return fields and behavior, which is useful but belongs to other dimensions.

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: compare the live 18k melted-gold price across Milli.gold, Wallgold, Melligold and Daric in Toman per gram. It also distinguishes the live snapshot use case from the sibling history tool, so an agent can identify the tool without opening the schema.

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 makes the primary use case explicit: comparing live per-gram gold prices. It also routes trend requests over a day, week or month to gold_milli_history, giving the agent a clear alternative when the current tool is not appropriate.

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