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

Discloses blast radius ("Every entry carrying it is rewritten in the same step"), the exact auth scopes required (content:publish for published entries, otherwise content:write), and an optimistic-concurrency precondition with a fallback read. These are behaviors not inferable from the annotations, which only say readOnly=false, destructive=false, openWorld=false.

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?

Behavioral facts are front-loaded in the first sentence, with the safety gate clearly delimited by a header. The prompt-injection boilerplate in the trailing paragraph is generic and consumes roughly a third of the text without tool-specific content.

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?

Covers the cascade semantics, permissions, and concurrency that matter for a 6-param mutation with no output schema and destructiveHint=false. Minor gaps remain: the collection parameter's meaning and whether the change is reversible by renaming back.

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?

At 67% schema coverage the schema leaves expected_version and the color palette undocumented, and the description fills both (enumerates red/gold/gray/black/green/blue/null and explains expected_version as the tag's version with 0 meaning unregistered). The collection parameter remains unexplained in both places, keeping it off a 5.

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 ("Rename a tag and / or set its colour") and immediately scopes it against the obvious sibling by referring to list_tags for version lookup. An agent can distinguish it from update_entry, list_tags, or create_entry without opening a schema.

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 [When to use] block gives an explicit gate (only when the user explicitly asks) plus the read-first precondition when expected_version is absent. It does not name a true alternative for the read side beyond list_tags, so it is clear but not a full when/when-not routing statement.

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