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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description adds value beyond that by disclosing what the response contains (checks, prep steps, primer/undercoat/top coats, what to avoid) and that supplying `cause` adds making-good steps plus an `urgency` value — behaviour an agent could not infer from the annotations alone.

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 core capability is front-loaded in the first clause before the enumeration, and the second sentence plus the example are efficient. The inline list of 12 surface values is long but earns its place by telling the agent the valid domain without opening the schema.

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 carries the burden of describing returns, and it does so only in outline. For a 4-parameter tool with a nested `trade` object, the missing explanation of singular-vs-array surface selection and of the trade parameter's purpose leaves real gaps for correct invocation.

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 50%. The description usefully restates all 12 surface enum values and explains the concrete effect of `cause` (adds making good steps and an `urgency` value), which the schema does not. However, it is silent on the relationship between `surface` (singular) and `surfaces` (array) — a critical ambiguity — and never explains why a read-only checklist accepts a `trade` business-profile object.

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 a specific resource and scope: surface preparation plus the paint system (primer, undercoat, top coats) and pitfalls, enumerated across 12 named surface types. It is clearly a reference-lookup tool, unlike the calculator-style siblings (paint_quantity, job_estimate), but it never explicitly distinguishes itself from them, so it falls short of a 5.

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 implied rather than stated: the example call shows how to query multiple surfaces at once, and the `cause` sentence hints at when to add damage context. There is no explicit when-to-use, when-not-to-use, or naming of an alternative sibling for related questions (e.g. lead paint risk or exterior weather).

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