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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds one genuine behavioral fact beyond them: the payload includes the unreviewed rows the rule is suggesting, which hints at the intended review flow. It says nothing about what happens for an unknown or already-ended rule_id, nor about row volume.

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 short clause with zero padding, which is good, but it is a sentence fragment rather than a front-loaded statement, and a verb would cost a single word while removing real ambiguity. Brevity here shades into under-specification.

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 one-parameter, read-only lookup with full annotation coverage and a 100%-described schema, the description covers the essentials. With no output schema, however, the return shape rests entirely on the phrase 'with the unreviewed rows', which leaves the agent guessing at field structure and whether accepted suggestions drop out of the response.

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% and the schema already gives the format hint 'e.g. RL-0001', so the single parameter is adequately documented. The description adds no further meaning about rule_id (e.g. that it must reference an active rule), which is the baseline-3 outcome when the schema does the work.

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 phrase 'One rule with the unreviewed rows it is suggesting for' identifies the resource (a single standing rule) and what is bundled with it (pending suggested rows), so the gist is recoverable. But it is a noun fragment with no verb ('get'/'fetch'), and it draws no line against purch_rules, purch_accept_suggestions, or purch_review_batch, so an agent must infer that this is the single-item lookup.

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?

There is no statement of when to call this versus purch_rules (list) or purch_accept_suggestions (act on the suggestions this tool returns). The natural workflow — fetch the rule to inspect proposed rows before accepting — is nowhere stated, and there are no exclusions or prerequisites.

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