Reorder screenshots

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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false. The description adds real context beyond them: the ASC_WRITE=1 auth requirement and the fact that already-applied steps are skipped on re-run. The 'safe to re-run' line partially restates idempotentHint, which keeps it from a 5.

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?

Front-loaded with the core action, then the parameter semantics, then the safety/auth note. Every sentence carries weight and the example is compact. Slightly compressed wording ('after them') costs a little clarity, but nothing is wasted.

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 7-parameter mutation tool with no output schema, the description covers the non-obvious parameter, the required write scope, and re-run safety. It does not describe the return payload of dry_run or a normal run, which is a minor gap given no output schema exists to carry that information.

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 coverage is 86%, so the baseline is 3, but the description meaningfully explains the one parameter the schema leaves undocumented: 'order' accepts 1-based positions or screenshot IDs, unlisted items retain relative order, and '[4] moves screenshot 4 to the front.' That is genuine semantic value beyond the schema, including the otherwise-unexplained mixed integer/string union.

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 states a specific verb and resource ('Changes the order of a screenshot set'), which clearly separates it from sibling mutators like upload_screenshots, delete_screenshots, and replace_screenshot. It is clear but never explicitly names or contrasts with those siblings, so it stops short of a 5.

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?

Usage is implied by the ordering semantics and the worked example, so an agent can infer how to call it. However, there is no explicit when-to-use guidance, no prerequisites beyond the write scope, and no routing to alternatives such as replace_screenshot when the goal is substitution rather than reordering.

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