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

Annotations already flag destructiveHint=true and openWorldHint=true, so the bar is lower, and the description still adds genuine value: it discloses that missing names are created as a side effect (unless create_missing is false) and that confirm:true is mandatory before touching the live site. It stops short of saying that replace mode discards existing terms, which is the most consequential side effect.

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?

Three short sentences with zero filler, and the most important fact — this is a write to the live site — is front-loaded in a bracketed marker. The confirm requirement and creation side effect follow in dependency order.

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 six-parameter mutation tool with no output schema and full schema coverage, the description covers the risk profile, the confirmation gate, and the implicit creation side effect. The one gap is that replace-as-default (which can remove existing taxonomy assignments) is left to the schema rather than surfaced in prose.

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 schema already documents all six parameters, including the mode enum and create_missing default. The description reinforces the name-or-id input format and the auto-creation behavior but adds no syntax or default detail beyond the schema; baseline 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 ('Set or add categories and tags on a post') plus the accepted identifier forms ('by name or id'). It is clearly distinguishable from siblings like wordpress_update_post or wordpress_list_taxonomies, though it never names an alternative explicitly.

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 prefix '[WRITE — changes your live site]' and the 'Requires confirm:true' clause tell the agent this is a live mutation needing user confirmation, which is real usage context. However, there is no guidance on when to prefer this over wordpress_update_post for content changes, or when replace vs add is appropriate (that is left entirely to the schema).

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