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

Annotations already cover the read-only/idempotent safety profile, and the description goes well beyond them: sources differ in AUTHORITY (issuer catalogues vs. aggregated observation rows with no KYC gate and no custody claim), targetArea is a stated audience and never an eligibility check, and identity fields are absent rather than zero. This is exactly the extra behavioral context annotations cannot convey.

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?

Front-loaded with the core question, then the scope, then the alternative. The three numbered points are long but each carries decision-relevant content; the third point partly restates output semantics that the output schema already covers, which is the only real padding.

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 an output schema present, the description need not explain return values, and it still covers scope, authority tiers, issuer multiplicity, pagination hints via the schema, and sibling routing. Nothing an agent needs to call this correctly is missing.

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% and the enum params (line, issuer) are already documented in the schema, so baseline 3 applies. The description reinforces issuer semantics conceptually ('Report the issuer, not just that the token exists') but adds no syntax, defaults, or format detail beyond the schema.

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+resource ('Does a tokenized version of a given company, ETF or bond exist, and from which issuer?') and enumerates the tiers it searches, so the agent can distinguish it from search_yield_products and the compare_* siblings immediately.

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 usage: 'Use this BEFORE saying a stock is not available on-chain' and 'For instruments that do carry a comparable rate, use search_yield_products instead.' Both the when-to-use and the alternative-with-condition are stated outright.

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