Query item facets

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is free; the description adds real behavior beyond that — AND-combination of filters, omitted-axis semantics, newest-first ordering, and a return shape ('returns yoinks and count from local storage'). The 'yoinks' return term is unexplained jargon, which costs a point.

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?

Four short sentences, front-loaded with the action and scope before the routing advice, and every sentence carries distinct information. Slightly dense with sibling names in one clause, but nothing is redundant.

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 correctly states the return shape and count, and it resolves the main risk of a seven-optional-param tool by explaining combination and omission. What remains thin is the value vocabulary ('yoinks', axis label values), which it delegates to get_facet_taxonomy rather than leaving unexplained.

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 per-parameter meaning is already documented and the baseline is 3. The description earns above baseline by adding cross-parameter semantics the schema cannot express: filters are AND-combined and an omitted filter leaves that axis unrestricted — exactly the ambiguity an agent would otherwise guess at with seven optional params.

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?

States a specific verb (List) plus resource (saved items) and the scope constraint (matching all supplied facet and tag filters, newest first). It also explicitly contrasts itself with search_uoinks, classify_facets and get_facet_taxonomy, so an agent can place it in the sibling set without opening a schema.

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?

Gives an explicit when-to-use condition ('exact stored-label selection') and names three alternatives with the condition that selects each: search_uoinks for text relevance, classify_facets to write labels, get_facet_taxonomy to discover axes. Both directions (use / use-instead) are covered.

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