Live quote and order book

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), and the description adds genuinely non-derivable behavior: units (rial per paper/share, market_value in rial), stale-after-hours semantics (shows the last session outside Sat-Wed 08:45-12:30 Tehran), empty order-book levels being dropped, and bond levels carrying per-price yield. That is exactly the context annotations cannot express.

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?

Four sentences, front-loaded with what it returns, then usage, then units, then edge cases. Every sentence carries a distinct, load-bearing fact with 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?

For a single-parameter, read-only snapshot tool with no output schema, the description covers return contents, units, staleness behavior, and data-shaping quirks. An agent could call it correctly and interpret the response without further guidance.

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?

With one parameter at 100% schema coverage, the schema already documents that the id comes from ifb_search or ifb_yields and accepts an exact trading symbol. The description restates units but adds no new constraint, format, or edge case for the parameter, so the 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 live trading data of one instrument') and enumerates exactly what comes back: last/closing price, change, volume, value, order book, and YTM for bonds. The word 'live' plus the 'what is it trading at now' framing implicitly separates it from the historical sibling (ifb_history) and the static profile sibling (ifb_instrument).

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?

Gives a clear positive use cue ('what is it trading at now' and 'best bids and offers') and indirectly routes the agent to ifb_search/ifb_yields for the instrument id. It never names a sibling it should not be used instead of, so there is no explicit exclusion, but the selection context is unambiguous.

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