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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real operational context beyond that — local WordPress authentication with no WooCommerce REST API keys required — but says nothing about what is returned (e.g. a currency code versus a settings object), which matters since there is no output schema.

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 short sentences, with the core purpose front-loaded. The second sentence carries auth details and a note about mirroring the woocommerce-mcp-server method; the mirroring reference is the least valuable part but is brief and arguably supports parity expectations.

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 read-only lookup with full schema documentation and a complete annotation set, the description covers purpose and auth prerequisites adequately. The only meaningful gap is the absent statement of the return value, which the lack of an output schema leaves undocumented.

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?

There is a single parameter and schema description coverage is 100%; the schema already explains that site_id comes from list_sites and is not a URL or post ID. The description adds nothing further about the parameter, so the baseline of 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?

States a specific verb and resource: "Retrieves the current WooCommerce currency." An agent knows exactly what it fetches. However, it does not differentiate from the sibling wc_get_currencies (which presumably lists all configured currencies), leaving the "current" vs "all" distinction to be inferred from the name alone.

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 implied by the word "current" and by the schema guidance to call list_sites for site_id, but the description never explicitly says when to use this instead of wc_get_currencies or any other settings-lookup sibling. No exclusions or alternatives are named.

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