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

Annotations already indicate readOnlyHint=true and openWorldHint=true, so the description need not repeat safety traits. The description adds value by specifying that it uses Futures mark price (not index price) for basis calculation, and that it 'error jelas' (errors clearly) for futures-only pairs. This clarifies the tool's computational behavior beyond the schema and annotations.

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 compact sentences deliver the core, the key comparison, and an important caveat. The structure front-loads the primary purpose and highlights the 'PENTING' warning without unnecessary fluff.

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 simple one-param read-only tool with full schema coverage, the description is quite complete. It covers the output concept (spot price + real basis vs mark price), differentiates from an index-price alternative, and alerts about a failure mode with a countermeasure. It misses nothing major, though output shape details are left unmentioned.

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%; the symbol parameter is fully documented in the input schema with format, example, and constraints. The description adds no extra parameter detail, so baseline 3 is appropriate.

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 opens with the specific resource and operation: 'Harga SPOT Binance + basis riil vs mark price Futures', which clearly identifies this as a spot price and basis computation tool. It explicitly distinguishes itself from binance_get_funding_rate by stating 'bukan harga index price rata-rata' (not average index price), helping differentiate it from a sibling tool that could easily be confused.

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 provides when-to-use context: 'bedain leverage-driven vs demand riil' (differentiate leverage-driven vs real demand). It also gives a clear exclusion: many futures pairs are futures-only without spot listing, and advises checking binance_check_spot_listing first if unsure. This is practical usage guidance, though it doesn't offer formal when-not-to-use scenarios beyond the futures-only case.

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