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

Annotations already cover readOnly, idempotent, non-destructive, and openWorld, so the safety profile is established. The description adds genuinely useful context beyond that: the exact fields returned and the underlying endpoint (GET /labels), which matters since there is no output schema.

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 tight sentences, front-loaded with purpose, followed by the cross-references and endpoint. Every clause earns its place with no repetition.

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 read-only list tool with no output schema, the description covers purpose, returned fields, and alternatives adequately. It could note ordering or pagination behavior, but nothing essential to invocation 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 100%, and the single 'notebook' parameter is fully documented in the schema with format and source tool. The description adds no parameter syntax or format details beyond what the schema provides, so the baseline 3 applies.

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 ('List') and resource ('labels'), then defines them functionally: 'labels that group a notebook's sources by topic,' and enumerates returned fields (id, name, emoji, source ids). It also names the sibling write tools, so an agent can distinguish it from create/update 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?

Provides clear context for when to use it (to list labels for a notebook) and routes to notebook_create_labels and notebook_update_label for the mutation cases. It stops short of an explicit 'when not to use' or pagination caveat, so it is clear but not exhaustively directive.

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