Full PSGC hierarchy for a place

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds behavioral insight about the return structure (the chain of administrative levels), which is valuable beyond annotations. It does not contradict annotations, and there are no hidden side effects implied.

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 description is a single, concise sentence that front-loads the action and output. It contains no filler, and every word contributes to clarifying the tool's purpose.

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?

Given the tool has a simple one-parameter schema, a clear output schema, and strong annotations (read-only, idempotent, open-world), the description fully covers the necessary context. It explains the hierarchical chain, and since an output schema exists, return value details are not required.

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 for the parameter is 100% since the input schema includes a description for psgc_code ('9-digit PSGC code (leading zeros optional)'). The description reinforces that it takes one PSGC code but adds no additional semantic detail beyond the schema, so the baseline 3 is appropriate.

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 clearly states the tool returns the full hierarchy chain (region -> province -> city/municipality -> barangay) for a single PSGC code. It uses a specific verb ('Return') and resource ('full chain'), and the hierarchical scope distinguishes it from location-related siblings like list_admin_units and resolve_ph_location.

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 description implies clear usage context: use this when you need the complete administrative hierarchy for one PSGC code. It does not explicitly mention when not to use it or alternatives, but the context is sufficient given the focused single-code input and the explicit chain output.

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