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 the payload-size claim ('< 1.5 KB') and the retention posture, which are genuinely useful, but it never says what the response contains or how 'no delta' is signalled.

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?

A single front-loaded sentence with no filler. It is dense but not padded, though the unexpanded acronyms compress meaning out rather than in.

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?

All parameters are optional and documented, and annotations cover the safety profile, so nothing critical is missing for invocation. The gap is behavioral: whether this returns a boolean heartbeat, a list of deltas, or per-provider breakdowns is left entirely to inference, and there is no output schema to fall back on.

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 all three parameters carry examples, so the baseline is 3. The description only echoes the 'since YYYY-MM-DD' semantics and adds nothing about how jtbds/providers interact or what happens when both are omitted.

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 verb ('checks whether') and the resource (watched providers/JTBDs with alerts, price changes, picks, receipts, gotchas) are specific, and the delta framing separates it from pure-state tools. However, coined terms like 'Zero-IP retention', 'E3/E4 outcome receipt' and 'pick update' are undefined, so an agent can't fully map them to sibling tools such as changes or freshness.

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?

'Heartbeat' and the 'since' framing imply a recurring polling use case, but no explicit when-to-use guidance is given. Siblings named changes, freshness, and check plausibly overlap and are never mentioned as alternatives or exclusions.

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