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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: results are ordered newest first, each aggregate is ed25519-signed under a named key (botsrated-prober-1), and raw signed receipts are retrievable via archive_url + line range + sha256. What is missing is anything about freshness/lag, rate limits, or free-tier constraints.

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?

One sentence, front-loaded with the pricing tag and the core noun phrase before the field inventory, so an agent gets the gist immediately. The long comma-separated field list is dense but each item is informative rather than filler; a light restructure (splitting the field list from the signing/archive clause) would make it scan faster.

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 carries the full burden of explaining return values, and it does so thoroughly — contents per day, ordering, signature scheme, and where the raw receipts live. Gaps are minor: no mention of response envelope shape, pagination/truncation when 'days' is large, or behavior for an unknown host.

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% — 'host' (hostname or URL, with an example) and 'days' (1-90 UTC days, default 30) are already fully documented. The description reinforces the single-host scoping ('one seller host') but adds no format, normalization, or boundary guidance beyond the schema, so the baseline of 3 applies.

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 gives a concrete verb+resource pair — 'Signed daily aggregates for one seller host, newest first' — and then enumerates exactly what each aggregate contains (probes, 402 counts, latency percentiles, payTo/asset/network, receipt ids, archive pointers). This is far more specific than the bare name 'history'. It does not, however, distinguish itself from siblings like 'report', 'coverage' or 'sample', which could plausibly also return historical data.

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 only implied: the leading 'FREE.' tag hints that a paid counterpart exists, and 'for one seller host' plus the 'days' parameter implies a per-host daily time-series use case. There is no explicit 'use this when…' statement, no named alternative, and no exclusion (e.g. whether this is the right tool for multi-host or per-request drill-down).

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