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

Annotations already declare this a safe, closed-world read operation, and the description is consistent with that. Beyond the annotations it discloses real behavioral facts: the quantity table used, that bond pattern applies corrections to both brick and mortar, that waste defaults differ for units vs mortar, and that units_per_bag=0 falls back to standard brick/block coverage.

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?

The purpose is correctly front-loaded in the first clause, but the majority of the text is a dense formula dump that an agent does not need in order to select or invoke the tool. It is one paragraph and not padded with filler, yet the formulas crowd out the usage routing that is missing.

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?

With no output schema, the description does the necessary job of naming the three returned quantities (units, cubic feet of mortar, bags). All seven optional parameters are documented at full coverage, and the read-only annotations require no further safety disclosure; only the exact response shape and the ordering/rounding of results are left implicit.

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 schema carries the defaults and enums, but the description goes further by showing how each input feeds the result: joint_in selects the table row, bond adds a multiplicative factor, and each waste percentage is applied to a different quantity. The 'Block = wall × 1.125' line is the weakest, since it appears without tying back to a named parameter.

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 opening clause states a specific verb and resource: compute mortar quantities (units, cubic feet, bags) for a brick or concrete block wall, and even names the data source (BIA Table 4). It is clearly distinct from generic siblings like calc_grout, but it never names the closest sibling calc_brick, which it partially overlaps by also returning unit counts.

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 explicit when-to-use, when-not-to-use, or alternative routing. The agent must infer from the phrase 'Mortar for a brick or concrete block wall' that this is for masonry takeoffs, and nothing tells it whether to prefer calc_brick or calc_concrete_block for the unit-count portion.

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