Assign taxonomy terms to a WordPress post by site ID, post ID, taxonomy, and term IDs, with optional append or replace behavior.
Assign taxonomy terms to a post
| Name | Required | Description | Default |
|---|---|---|---|
| site | Yes | Site id (see list_sites) | |
| terms | Yes | Array of term IDs | |
| append | No | Append to existing terms (false = replace) | |
| post_id | Yes | Post ID | |
| taxonomy | Yes | Taxonomy name |
Changes observed during successful MCP inspections.
v3.4.0Input schema / properties / siteAdded value: +{
+ "description": "Site id (see list_sites)",
+ "type": "string"
+}Input schema / requiredPrevious value: -[
- "post_id",
- "taxonomy",
- "terms"
-]New value: +[
+ "site",
+ "post_id",
+ "taxonomy",
+ "terms"
+]v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. 'Assign' implies a mutation, but the description never discloses the significant default that append=false means existing terms are REPLACED — a destructive side effect the agent cannot anticipate from the prose alone. Permissions and return behavior are also unstated.
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?
A single tight sentence with no wasted words and the core operation front-loaded. It is efficient, though its brevity contributes to the missing behavioral context.
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 mutation tool with no annotations and no output schema, the description is too thin: it omits the replace-vs-append default, prerequisites, and any error or permission context. An agent could invoke it correctly only by reading the schema closely.
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 description coverage is 100%, so all five parameters (including the append default and its replace semantics) are already documented in the schema. The description adds nothing beyond that baseline, which is the expected 3.
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 (assign) and resource (taxonomy terms) and the target (a post), so the agent can identify the operation immediately. It has no direct sibling doing the same job, so no differentiation is needed, but it stops short of mentioning scope like site or taxonomy 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?
There is no when-to-use guidance, no stated prerequisites (e.g. that a site id from list_sites is required), and no pointer to mcp_list_terms for discovering valid term IDs. The agent must infer everything from the schema.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.