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

Annotations already declare readOnlyHint and openWorldHint, so the description correctly avoids repeating those. It adds valuable behavioral details: the rolling-hour free limit, that repeats stay free, the BREADTH_LIMIT error on exceeding the limit, the existence of a paid snapshot path, and the omitted-ticker list behavior. No contradiction with 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?

The description is three sentences, front-loaded with the core return content and then covering rate limits and the omitted-ticker case. It is efficient with no fluff, though the second sentence is dense and packs multiple conditions (three free, repeats free, fourth returns BREADTH_LIMIT, paid path). Slightly heavy but still well-structured.

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 must explain what is returned and any call-specific constraints. It lists the return components, explains the rate limit and error behavior, and covers the omitted-ticker edge case. For a single-parameter tool with optional input, this is complete enough for an agent to call it correctly without additional documentation.

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 coverage is 100% and the ticker parameter already has a description covering case-insensitivity and the omit-for-list behavior. The tool description reinforces this but adds no new parameter-specific semantics beyond what the schema provides. The rate-limit context applies to overall usage, not to parameter meaning, 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 states a specific verb ('Returns') and resource ('free frozen-contract state view for one tracked tokenized treasury'), and lists concrete contents (identity, yield basis result, evidence cells, deployments, dates). It also clarifies the singular scope and the omitted-ticker behavior, which distinguishes it from the plural sibling get_rwa_instruments without needing to open schemas.

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 clear context: it explains the free-tier rate limit, the BREADTH_LIMIT error on the fourth ticker, and the alternate paid path. However, it does not explicitly name sibling tools or state when to prefer this over get_rwa_instruments or get_rwa_history. The guidance is implicit rather than explicit about alternatives.

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