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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds useful behavioral context: it returns the same document shape as fetch, and it 'missing lists ids that were not found' — meaning it tolerates missing ids and reports them rather than failing. This goes beyond the annotations and helps the agent predict behavior.

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 sentences, each earning its place: what it does, when to use it, and when to use the alternative. The key constraint (up to 20 ids) is front-loaded, and there is zero filler.

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 batch read tool with a single parameter, an output schema, and annotations covering safety and idempotency, the description is complete. It covers the batch limit, the missing-id behavior, the relationship to fetch, and the use case. Nothing an agent needs to call it correctly is missing.

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 does: it explains the ids parameter is a list of bookmark ids, caps the count at 20, and clarifies the behavior for missing ids. It doesn't spell out the UUID format, but the schema's pattern already covers that, so the description adds the semantic meaning that matters.

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 fetches complete content for up to 20 bookmark ids in one call, and explicitly distinguishes it from the sibling 'fetch' by noting the same document shape and the preference for 'fetch' with a single id. This gives an agent a precise verb, resource, and scope.

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 explicitly says when to use this tool ('when comparing or summarizing several saves from search or list results') and when not to ('For a single id, prefer fetch'). It also names the sibling alternative, making the routing decision unambiguous.

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