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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the agent knows this is a safe, closed-world read. The description adds the currency (CAD) and the fact that the data is a published fee schedule, but says nothing about return shape or completeness of the schedule. Given the annotations carry the safety profile, a 3 is fair.

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?

Two sentences, zero padding, with the primary purpose front-loaded and the optional filter second. Every clause earns its place.

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 one-parameter, annotation-backed read tool with no output schema, the description covers purpose, currency, and filtering adequately. The only minor gap is that it doesn't hint at the structure of the returned fee schedule, which an agent might want when presenting results.

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 single parameter already has an enum of valid service ids, so the schema does the heavy lifting. The description adds real value by naming get_services as the source of those ids and confirming the filter is optional.

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 (returns), resource (published fee schedule) and scope (Canadian dollars), which is enough for an agent to distinguish it from its sibling lookup tools. It also cross-references get_services, which anchors the tool within the family.

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 tells the agent that filtering is optional and where the filter value comes from ('one service id from get_services'), which implies the correct call order. It does not state explicit when-not-to-use conditions, but for a simple lookup tool the context is clear.

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