Quote a button

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

readOnlyHint=true and openWorldHint=true already tell the agent this is a non-mutating, externally-priced query, so the bar is lower. The description usefully discloses the dual return (price + whether the position is free), but says nothing about currency, billing period implied by the price, whether a quoted price is held/reserved, or any rate limits on an open-world pricing call.

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?

A single front-loaded sentence with no filler, leading with the price outcome and appending the availability outcome. Slightly awkward phrasing ('Price for a button... and whether that exact position is free') but nothing wasted.

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 5-parameter, read-only pricing tool with no output schema, the description covers both outputs at a high level, which is the minimum an agent needs. It still leaves gaps on price units/currency and on the x_px/y_px pairing rule that determines whether an availability answer is returned at all.

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 60%, and width_px/height_px carry no descriptions at all (height_px is only a $ref). The description reinforces that size and plan drive the price and that position determines the availability answer, but it adds no detail beyond the schema's own enum discount note and the 'omit x_px to only get the price' hint.

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?

Names a specific action (quote a price) on a specific resource (a button of given size and plan) plus an availability check at that exact position. This implicitly separates it from find_free_spots (searching for free areas) and create_checkout_link (purchasing), but the description never names those siblings, so the differentiation is left to inference.

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 is only implied: an agent can guess this is the tool for pricing a known size/position versus find_free_spots for discovering available areas. There is no explicit when-to-use, when-not-to-use, or named alternative, and no statement that this is the pre-purchase step before create_checkout_link.

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