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

With no annotations the description carries the full burden, and it delivers real behavioral context: slug and hierarchical are immutable, existing terms are not relocated, and rewrite/singular/plural remain editable. It omits permissions, reversibility, and failure behavior, keeping it out of 5 territory.

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?

Front-loads the key partial-update rule, but the middle clause rambles ('it is invisible to visitors anyway — what they see is rewrite...'), diluting focus with explanatory asides. Functional but not tight.

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?

An output schema exists, so return values needn't be explained, and the description covers mutation semantics and immutability. But it explicitly defers to get-skill-doc for rules and leaves three parameters undocumented, so it is not self-sufficient for a no-annotation mutation tool.

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 only 25%, so the description must compensate, and it does clarify slug (immutable identifier), postTypes (full replacement set), and rewrite/singular/plural roles. However, public, showInRest, and showAdminColumn are left undocumented in both schema and description, so the gap is only partly closed.

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+resource ('Update a taxonomy Fabrement created') and scopes it to taxonomies the system owns, which cleanly separates it from create-taxonomy and delete-taxonomy. It does not explicitly name a sibling to disambiguate against, so it falls short of a 5.

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?

Gives concrete operating guidance: 'send only what changes' and 'postTypes is the FULL set (replaces)', which tells the agent exactly how to invoke it. It also routes the agent to get-skill-doc before the first call. No explicit when-not-to-use statement, so not a 5.

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