Instrument details and coupon schedule

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

Annotations already declare the safe read-only, idempotent profile. The description adds useful behavioral context beyond that: coupon_schedule rows contain per-paper rial amounts and the last row also repays face value, next_coupon is the first on or after today, and live=true triggers one extra 3 MB page and is slower. It does not discuss rate limits or partial-failure behavior, keeping it short of 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?

The description is front-loaded with the primary purpose and then adds routing and return-format details in a compact two-paragraph form. Every sentence carries information, though the second paragraph is dense and could be slightly tighter.

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?

There is no output schema, so the description must explain return values; it does so for coupon_schedule, next_coupon, and the live-share case. It lists the basic instrument fields and covers the main edge behavior, but does not explain missing-instrument handling or other failure modes, leaving a small gap.

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 the baseline is 3; however, the description adds genuine meaning beyond schema: it clarifies what live=true returns for a share (quote, price band, P/E, industry peers) and ties coupons=true to the detailed row semantics of coupon_schedule. It does not fully restate every parameter's behavior, but the added output-oriented context is valuable.

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 ('Describe one Fara Bourse instrument') and enumerates the returned fields (name, ISIN, market, coupon rate, maturity, issuer, guarantor, payment schedule). It clearly distinguishes itself from siblings like ifb_yields, ifb_search and ifb_quote by explaining when to call each.

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?

It explicitly says to use it after ifb_yields or ifb_search, and gives a concrete routing rule: pass live=true for a share to get the quote and peers in one call, otherwise call ifb_quote for live price and order book. This is exactly the kind of when-to-use and alternative-tool guidance an agent needs.

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