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

Annotations already declare readOnly/idiempotent/non-destructive, so the description correctly focuses on added context: zero-padding to GTIN-14, the gated response shape, the 'pack/size VALUE is NEVER returned' guarantee, and fail-closed brand matching with uncertainty mapped to recognized:false. This is meaningful disclosure beyond the annotations, with no 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?

Dense and efficient: branches are labeled, the never-returned value is front-loaded, and the fail-closed policy is a single closing clause. Slight deduction for jargon density ('SPARKS', 'GSC', 'BPC', 'Map Navigator') that may cost an agent a parse, but every sentence earns its place.

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 an output schema present (so return values need no explanation) and a single fully-documented parameter, the description covers the two behavior branches, gating logic, and matching policy thoroughly. The only minor gap is not spelling out what the GALICIA license record in Branch A contains, though the output schema likely covers it.

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 the baseline is 3. The description restates the zero-padding behavior that the gtin parameter schema already documents, adding no new parameter semantics beyond what the schema and behavior descriptions provide. No deduction is warranted since the schema already carries the load.

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 and resource ('Two-branch SPARKS resolver') and precisely scopes the behavior with named Branch A (GSC Territory/License GTIN) and Branch B (third-party BPC GTIN) paths. Being SPARKS-specific cleanly differentiates it from siblings like resolve_gtin, resolve_node, and resolve_scope without requiring schema inspection.

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?

The two-branch breakdown effectively tells the agent which GTINs route where, and the explicit 'Route to Navigator' instruction gives downstream guidance. It doesn't name sibling alternatives directly (e.g., when to pick resolve_sparks over resolve_gtin), but the internal routing logic is clear enough for this one-parameter tool.

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