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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description adds useful computational behavior — that rates are per 1,000 sq ft, that purity and germination from the seed tag are multiplied into pure live seed, and that bag counts round up. It stops short of explaining edge behavior such as what happens when the bag size is left at its zero default.

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 the question the tool answers, followed by the formula chain. Density is high and little is wasted, though the run of three formulas in one sentence is slightly compressed for skimming.

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 five-parameter, fully-defaulted, no-output-schema calculator, the description supplies the underlying computation, which effectively conveys what the tool returns. The remaining omission — output units, whether bag counts appear when bag_lb=0 — is minor but real.

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 a 3 baseline would suffice, but the description adds real meaning: it tells the agent where purity_pct and germination_pct come from (the seed tag) and how they enter the formula via PLS. The one gap is bag_lb, whose 0 default is never explained in terms of the bag-count output.

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 opens with a specific verb-and-resource statement ('How much grass seed to buy for a new lawn') and immediately scopes it to new lawns with university seeding rates. It is clearly distinguishable from adjacent siblings such as calc_sod and calc_lawn_fertilizer without opening the 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?

'For a new lawn' implies the boundary (establishment, not overseeding or fertilizing), but the description never states when not to use it or names an alternative tool. Usage is implied rather than prescribed.

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