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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower. The description adds real value beyond them: the 30-docId cap and the default return shape (compact metadata + chunksPreview) with an opt-in for full bodies. It stops short of describing error behavior past the cap.

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 tight sentences with zero waste, front-loading the fan-out purpose, the cap, and the return-shape toggle in order of importance.

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?

With a read-only annotation set and no output schema, the description usefully compensates by describing the return shape (compact metadata + chunksPreview vs full bodies). Sufficient for an agent to call it correctly, with only edge-case error handling left unstated.

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 the schema already documents all three parameters. The description reinforces the 30-docId limit and clarifies includeContent's effect on return shape, but adds little beyond what the schema states.

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 and resource (fetch KB documents) plus the distinguishing mechanism (many in one call / fan-out). It clearly implies bulk-vs-single against get_kb_doc, though it doesn't name the sibling or distinguish from list_kb_docs/search_kb_docs explicitly.

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 clear usage context: use for fetching many at once, and set includeContent=true when full bodies are needed versus the compact default. Lacks explicit when-not guidance or named alternatives (e.g., get_kb_doc for single fetches).

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