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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), yet the description adds rich behavior: hours are computed against America/New_York, it discloses coverage.completeness semantics, verifiedDaysAgo/hoursConfidence staleness signaling, verdictCaution and sourceCaveat caveats, and the instruction to surface phone and advise ringing first. This is well beyond what annotations provide.

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 what the tool is and when to call it, and every subsequent sentence carries a substantive caution (the single ED, Riverhead vet, timezone clock, coverage gaps). It is dense and long, but the length is largely earned by the hallucination-risk warnings, so it stops short of padding.

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?

There is no output schema, so the description must carry the return contract — and it does: it names openState, closesAt, opensAt, coverage.completeness, verifiedDaysAgo, hoursConfidence, verdictCaution, and sourceCaveat, plus the 911/medical-advice guardrails. Nothing an agent needs to call and interpret this correctly is missing.

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%, so the enum meanings and town-sorting behavior are already documented in the schema. The description reinforces the palettes implicitly but adds no syntax or format detail beyond the structured fields; baseline 3 is correct.

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 resource (where to go for care on the East End) with four concrete modalities (ED, urgent care, pharmacy, emergency vet) and the computed fields it returns (openState, closesAt, opensAt). An agent can distinguish this from the generic whats_open_now sibling without opening either 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 a vivid, explicit trigger list ('hurt, sick, cut, tick bite, stitches, a prescription to fill, a pharmacy still open tonight, or a dog or cat in trouble'), which is clear usage context. It does not explicitly contrast against the closest sibling (whats_open_now), so it falls short of a full when/when-not/alternatives statement.

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