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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description adds value by explicitly stating 'Does NOT mutate any state' and 'Returns the Shippo API response', providing additional behavioral context beyond the 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 concise, with only a few sentences that front-load the purpose and follow with clear usage instructions. Every sentence adds value; no unnecessary words.

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?

Given the presence of an output schema and annotations, the description covers all necessary aspects: what the tool does, how to use it correctly, prerequisites, and error conditions (rejection). It is fully complete for an effective tool definition.

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%, so the baseline is 3. The description adds no additional parameter semantics beyond repeating the schema's description: 'Read-operation short name' and 'Operation arguments per its inputSchema.' This does not improve upon 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?

The description clearly states it executes a READ-only Shippo API operation (List*, Get*, Validate*, Parse*, etc.) and returns the Shippo API response, explicitly noting it does not mutate state. This distinguishes it from the sibling tool shippo_write_execute_tool.

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 explicit guidance: use only for 'read' operations per shippo_describe_tool, warns that write operations will be rejected, and directs to shippo_list_tools for operation names and shippo_describe_tool for argument shapes. It also mentions case-insensitive name lookup.

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