Plan local/Drive sync

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

Annotations already declare readOnlyHint and idempotentHint, but the description goes well beyond them: it defines the diff categories (only local, only Drive, changed), the 'maybe changed' tolerance rule (same size, mtime >2s apart), that symlinks are skipped, and that byte totals and completeness are computed. This is exactly the behavioral detail an agent needs and the annotations cannot supply.

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?

Extremely dense but front-loaded: the safety statement ('Read-only plan, transfers nothing') leads, followed by the diff semantics. Every clause carries information and there is 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?

With no output schema, the description usefully outlines the return content (diff categories, byte totals, completeness). It covers the core read-only semantics and side effects, leaving only minor gaps such as pagination/limit behavior, which the schema already supplies.

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 limit, ignore, compare, and direction. The description adds meaningful semantics for the comparison result ('maybe changed' at >2s mtime skew) but says nothing about limit, ignore globs, or direction, so it adds only marginal meaning beyond structured fields.

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 names a specific verb and resource — 'diff a local folder against a Drive folder' — and immediately states the scope ('Read-only plan, transfers nothing'). No sibling tool does local-vs-Drive comparison, so it is unambiguous without opening the 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?

'Read-only plan, transfers nothing' implicitly signals this is the preview step before an actual transfer, which is useful context. However, it never states when to use this versus a direct operation, nor names a follow-up or alternative tool, so guidance is only implied.

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