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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuine value beyond that by enumerating the returned content, including the notable detail that interest rates are given for every interest period that has already started. It does not say what happens for an unknown or retired series code, which would have earned 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?

A single front-loaded sentence that states the resource, the keying parameter, examples, and the returned fields with no filler. Nothing could be removed without losing information.

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 correctly compensates by listing what the response contains, and the single parameter is fully covered. The only gap is edge behavior for invalid or historical series codes, which an agent would want to know before calling.

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?

Only one parameter exists and the schema documents it at 100% coverage with its own example, so the schema carries the load. The description reinforces this with two concrete codes (EDO1136, COI1130), confirming the expected code format, but adds no syntax or lookup rules beyond that. 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?

The description names a specific verb+resource ('Details of one Polish retail treasury savings bond series by its code') and enumerates exactly which fields are returned (terms, margin, early redemption fee, per-period interest rate). The word 'one ... by its code' implicitly separates it from the sibling offer-listing tool, but that contrast is never made explicit.

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?

Usage is only implied: an agent infers it should call this when it already has a series code and needs the terms. There is no statement of when to prefer get_polish_savings_bonds_offer instead, nor any prerequisite or exclusion, so the agent must reason about routing on its own.

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