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

Annotations already declare destructiveHint=true and readOnlyHint=false, so safety is covered; the description then adds genuinely new semantics — that omitted fields are preserved and each supplied field overwrites its prior value, including the keywords array. It stops short of saying whether updates are reversible or what the response contains, so not a 5.

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, front-loaded with what can be changed, then the partial-update rule, then the scope exclusion. No filler and nothing repeated.

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 7-param mutation tool with full schema coverage and annotations carrying the destructive/read-write profile, the definition covers what can change, how omission is treated, and what is out of scope. Missing only return-value shape and per-operation preconditions (e.g. whether a published article can be reverted to draft).

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 every parameter is documented in the schema; the description's field list and the 'draft, ready or published' status values largely restate it. Only the overwrite-on-send semantics adds meaning beyond the schema, so the baseline 3 is right.

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 (Update) plus resource (article) and enumerates exactly which fields are mutable (title, slug, status, keywords, meta description, summary). It also carves out scope with 'The body is not editable here,' which separates it from article-content tools and from siblings like publish-article.

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?

'Only the fields sent change; each one overwrites its old value' tells the agent this is a partial/PATCH-style update rather than a replacement, which is the key usage decision. It also signals an exclusion (body not editable) but does not name the alternative tool or state prerequisites such as required permissions or which article states can be updated.

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