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

Adds real value beyond annotations: 'Returns metadata only, never bytes or download URLs' and 'Requires your API key,' plus the implicit truncation signal from the 1000 cap. Annotations already cover readOnly/idempotent, so this extra return-shape and auth context is the right supplement; pagination behavior past 1000 isn't spelled out.

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, each earning its place: purpose, use case, return contract. Front-loaded with the core action and no 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?

No output schema exists, so the description explicitly compensates by stating what is returned (metadata only, no bytes or URLs). Combined with the cap and auth note, an agent has everything needed to call it correctly.

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?

One optional parameter with 100% schema description coverage, so the schema already carries the api_key details. The description reinforces auth with 'Requires your API key' but adds no field-level nuance, consistent with a baseline 4 for a well-documented single param.

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 plus scope details: 'List this account's files, newest first, up to 1000.' The ordering and cap make the behavior concrete, and 'this account's' scopes it against the sharing siblings like list_shares.

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?

'Use this to find a file_id before sharing' gives a clear triggering condition and implicitly routes the agent away from share-management tools. It stops short of naming an explicit alternative or exclusion (e.g., when to use list_shares instead), so not a 5.

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