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

Annotations provide readOnlyHint=false (write) and idempotentHint=true, so the description does not need to repeat these. It adds the useful detail that archive state is 'reversible', which conveys behavior beyond what annotations state. It does not describe failure modes or side effects, but given annotations cover idempotence and safety, this level is appropriate.

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?

Two sentences with no fluff. The purpose is front-loaded in the first sentence, and the second sentence packs the tag-reuse guidance that prevents common errors. Every word earns its place.

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?

Given the tool's moderate complexity (5 params, nested tags object, output schema present), the description covers the essential fields and the key semantic nuance about tags. Annotations carry the idempotence and write context. The only gaps are minor: no explicit mention of the tags sub-operations (add/set/remove) behavior, but these are self-explanatory from the schema. Overall, an agent can call this correctly with the provided information.

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 0%, so the description must compensate. It clarifies that tag values are tag names and that they should reference existing names, which is valuable for the tags parameter. However, it does not elaborate on semantics for note, archived, or isFavorite beyond listing them, though their meanings are fairly intuitive. The description partially compensates for the coverage gap but leaves some parameters under-explained.

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?

The description clearly states the tool updates a bookmark's note, favorite state, tags, or reversible archive state. It identifies the resource (bookmark) and the specific fields, and contrasts with the sibling archive_bookmarks by emphasizing 'reversible', distinguishing the operations. The verb 'update' plus field list makes it unambiguous.

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 description gives partial usage guidance: it advises using list_tags to reuse existing tag names rather than inventing near-duplicates, which informs when to consult another tool. However, it does not explicitly state when to choose this over save_bookmark or archive_bookmarks, leaving the differentiation implicit. The 'reversible' hint helps, but no explicit exclusions or alternatives are named.

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