refine_scan

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

Goes well beyond the annotations. It discloses that each refine returns a NEW scan_id, that the prior result set remains live, and that shrinking to zero is recoverable — behaviorally important and consistent with idempotentHint=false and readOnlyHint=true. It also quantifies expected convergence (two or three rounds) and the performance profile versus a fresh scan.

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?

Purpose is front-loaded and the body is dense with usable detail, but the framing line 'and it is what makes the whole workflow work' and 'The second step, repeated.' add rhetorical padding without new information. Every other sentence earns its place.

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 an output schema present, return values need not be re-explained, and the description already covers the key one (new scan_id). Combined with full parameter semantics, workflow guidance, and the retry/lineage model for previous scan sets, an agent has everything needed to invoke this 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 0%, so the description must carry the load, and it does: scan_id is the set to narrow, scan_type is the comparison sharing scan_value's names with a str/bytes restriction to exact/not_exact, value is the comparison target, and end_value is the upper bound for between/not_between. All four params are given meaning absent from the schema.

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 (narrow an existing result set) and positions it precisely as the follow-up to a fresh scan. It names the sibling whose scan_type vocabulary it shares (scan_value) and explains the core distinction: it re-reads existing addresses rather than walking memory, so it cannot find what the original scan missed.

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 an explicit workflow trigger (change the value in the target — take damage, spend a coin — then keep addresses that changed to match) and an explicit exclusion (it cannot find addresses the original scan missed, so use a fresh scan for that). It also documents the retry path: the previous set stays live when a refine narrows to zero.

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