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

The description discloses several non-obvious behaviors beyond the annotations: results are sorted oldest-first for resumability, only additions/removals are reported, silent edits are not detected, and exits are unsupported. These caveats are essential for correct use and go well beyond readOnlyHint and openWorldHint.

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?

The description is dense but every sentence earns its place: core purpose, usage guidance, ordering/resumability, limitations, and exclusions. It is front-loaded with the most important scoping statement.

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 sync tool with no output schema, the description covers all essential context: when to use it, how to resume, what data is included, what is silently missed, and what is unavailable. An agent has enough information to call and interpret results 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?

Schema description coverage is 100%, so the schema already documents since, after, type, and limit. The description reinforces the resumable nextCursor behavior and the meaning of 'since', but does not add substantial new parameter semantics beyond what the schema provides.

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 uses a specific verb plus resource: 'Incremental sync: what was ADDED or REMOVED since a timestamp.' It clearly distinguishes itself from repeated search_rounds calls, which is the main sibling it could be confused with.

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?

Explicitly states when to use it: 'Use this — not repeated search_rounds calls — when you keep a local copy in step with the dataset.' It also names an exclusion: exits are not available because that table has no ingestion timestamp.

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