list_taxes

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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description adds value by disclosing the 'INVENTORY_R' permission requirement and the exact output composition (raw rate + computed percent). This goes beyond the annotations, satisfying the lower bar for behavioral disclosure given the presence of 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 a single, well-structured sentence that front-loads the core action ('Return the merchant's tax rates') and immediately adds valuable detail ('raw rate + computed percent') and the permission requirement. Every word earns its place with no redundancy or 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 parameterless read-only list tool with a good output schema and annotations, the description is fully adequate. It states what data is returned, the permission needed, and the purpose. No missing information would hinder an agent's ability to select and invoke this tool correctly.

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?

The tool has zero parameters and the schema is empty, so the 100% schema coverage makes parameter documentation moot. The baseline for 0-parameter tools is 4, and the description doesn't need to add anything about parameters since there are none.

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 the tool returns the merchant's tax rates, specifying they include both raw rate and computed percent. This specific verb+resource combination (Return + tax rates) makes the purpose unambiguous and distinguishes it from all sibling tools, none of which deal with taxes.

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 that this is a read-only list operation for tax rates, appropriate whenever that data is needed. The INVENTORY_R permission requirement gives a practical prerequisite. Since no alternative tax tool exists among siblings, explicit exclusions are unnecessary, though the description doesn't explicitly mention when not to use it.

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