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

Annotations already carry readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered structurally. The description adds real context beyond that: provenance of the ranges (Agria, AKC, Zoetis), the explicit 'not veterinary advice' scope limit, and a clear statement of what the computation returns. It doesn't discuss precision or edge behavior at the 8-week/24-month boundaries, which keeps it at 4.

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?

Three sentences, front-loaded with the core computation before the usage triggers and the disclaimer. The first sentence is long but every clause maps to a distinct output, so it earns its length; minor trimming of the provenance list would make it tighter.

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, yet the description fully specifies the return shape (total 24-hour sleep, night coverage, remaining nap hours, nap pattern for the age). Combined with the vet disclaimer and the source of the ranges, an agent has everything needed to call this correctly and to frame the result appropriately.

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 100%, so the baseline is 3, but the description adds semantics the schema lacks: it explains that 'wake' and 'bedtime' define how much of total sleep the night covers and therefore how many nap hours remain, which tells the agent why those seemingly optional params matter. The stated 8–24 month applicability band also reinforces the age constraint.

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-and-resource ('works out how much a puppy... typically sleeps per 24 hours') and enumerates the exact outputs: night coverage, remaining nap hours, and age-typical nap pattern. The subject matter is clearly disjoint from the only sibling, calculate_puppy_potty_schedule, so an agent can route 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?

It gives explicit trigger questions ('how much a puppy should sleep, how many naps it needs, or whether a puppy sleeps too much or too little') and an explicit exclusion: sudden sleep change or lethargy is routed to a vet, not this tool. Both the when and the when-not are stated.

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