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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavioral information: that the result set is a list of item keys intended to be fed into plan.furniture/plan.against — a return-shape disclosure that matters because there is no output schema. It stops short of stating result limits, empty-match behavior, or ordering.

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 tight sentences with zero filler. The query capability is front-loaded and the follow-on usage note is placed second, which matches the order an agent needs them.

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 one-parameter read-only search with no output schema, the description covers purpose, query syntax, and what the returned item keys are for. Marginal omissions remain around result count, no-match behavior, and multi-term semantics, but nothing essential for a correct first call is missing.

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 0% — the single "words" parameter is an undescribed string — so the description carries the full burden, and it largely does: it names example keyword values and documents an inline size syntax (w:1200) that is invisible in the schema. It leaves open whether size and keywords are combined in one string and how multiple terms are joined, which is the remaining gap.

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 gives a specific verb and resource ("Finds furniture in the catalog") and immediately shows the two query modes with concrete examples — keywords like bed/sofa/table and a size token like w:1200. No sibling tool touches furniture, so the agent can route here unambiguously.

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?

"Use the item keys with plan.furniture and plan.against" gives useful downstream workflow context — it tells the agent what to do with the results. However, it never frames when this tool should be chosen over another approach (e.g., vs. pulling a whole catalog), and no when-not guidance is present. Usage is implied rather than stated.

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