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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=false) by disclosing that it does not move the schedule, that re-running is idempotent because readings dedupe per time bucket, and that it can return `empty` or `needs_confirmation`. It stops short of explaining what `needs_confirmation` means or how the `approvalId` parameter resolves it.

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?

Four tight sentences, each earning its place: action, when to use, side-effect boundary, idempotency, possible return state. The core action is front-loaded and nothing is padded.

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 surfaces the two notable return states (`empty`, `needs_confirmation`) and the idempotency guarantee, which is enough to call the tool safely. The approval/confirmation flow around `approvalId` is the one unresolved piece an agent would still need.

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 67%; `id` and `workspace` are documented in-schema while `approvalId` is bare. The description adds no parameter-level meaning at all, and its mention of `needs_confirmation` never connects to `approvalId`, so it does not compensate for the coverage gap.

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 (run) plus resource (feed) plus scope ('immediately over its own window and record what it finds'). It is clearly distinguishable from ledger_feeds_backfill, ledger_feeds_preview and ledger_feeds_update without opening any 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?

Gives explicit timing guidance ('right after creating one to prove the mapping works') and names ledger_feeds_update as the follow-up for a failed mapping. It does not, however, contrast with the sibling ledger_feeds_preview, which is the obvious alternative for a non-recording test run.

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