ebay_get_shipping_services

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

readOnlyHint=true already tells the agent this is a safe read. Beyond that, the description adds real behavioral context: the validForSellingFlow=true filter constraint and the marketplace-specific localization requirement (acceptLanguage for EBAY_CA/EBAY_BE). This is the kind of value-add that goes beyond the annotation. Minor gap: no note on rate limits or output size.

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 purpose, then the important filter constraint, then localization, then the downstream use. All four sentences earn their place. Slightly dense but no filler.

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 read-only metadata tool with no output schema, the description covers purpose, return fields, filtering constraint, localization, and downstream usage — everything an agent needs to invoke it correctly. The absence of an output schema means more return-value detail would help, but the field enumeration largely compensates.

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 both parameters are fully described in the schema, including the acceptLanguage localization rules. The description reiterates the acceptLanguage guidance but adds no syntax beyond what the schema already states, 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?

States a specific verb+resource ('list the shipping services available on a marketplace') and enumerates the returned fields (carrier, category, domestic/international, shipping times, cost types, package limits). This clearly distinguishes it from siblings like ebay_get_shipping_carriers (carriers only) and ebay_get_shipping_locations.

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?

Provides a clear 'when' by naming the downstream consumer: 'Use the returned values when configuring fulfillment policies (ebay_create_fulfillment_policy).' It does not explicitly state when NOT to use it or contrast with the closely related ebay_get_shipping_carriers, but the intended use context is unambiguous.

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