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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safe, non-networked nature of the call is established structurally. The description's added value is the disclosure that results are a designer rule of thumb with sources cited via a linked page in the answer, which is genuinely useful output context. There is mild tension between 'the page linked in the answer' and openWorldHint=false, but a citation URL in the response is not an open-world interaction, so this does not rise to a contradiction.

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?

Two compact sentences, with both computed outputs (seat height, stool count) front-loaded before the caveat about sourcing. Nothing is redundant. The interrogative opening and the slightly meta reference to 'the page linked in the answer' keep it from being maximally crisp.

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 convey what comes back, and it does: two figures (seat height range and stool count). It also flags that the result is a rule of thumb rather than a precise spec, which is the key caveat for a simple calculator tool. Only the optional length parameter's effect on output is 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 description coverage is 100%, including the enum semantics for kind and the optional length, so the schema already does the heavy lifting. The description reinforces the meaning of height by tying it to the 10-to-12-inch rule and implies length drives the stool-count calculation. It adds framing but no syntax or units beyond what the schema already states, so baseline 3 applies.

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 names the specific computation: recommended seat height for a stool against a counter/bar, plus how many stools fit along it. The domain (bar-stool seating) is distinct from every sibling (ceiling_fan_size, rug_size, etc.), so no explicit sibling disambiguation is needed. It is phrased as a question rather than a verb+resource statement, which slightly softens it, but the intent is unambiguous.

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?

Usage context is implied by the domain and by the embedded rule of thumb (10 to 12 inches below the counter top), which tells the agent this is a planning/design calculation. There is no explicit when-to-use/when-not-to-use framing and no mention that this is a one-shot deterministic lookup rather than a search or measurement of a real space, but nothing misleads.

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