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

With readOnlyHint=true, the description's claim to 'retrieve metadata' aligns. It adds meaningful behavioral context beyond annotations: it clarifies that parentage is 'strict stored' (never invents edges), notes the tool does not return geometry (implied by 'For exact polygons use get_geometry'), and mentions 'No payment required.' This is helpful over and above the read-only flag.

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 multi-sentence but every sentence earns its place: it leads with the tool's role, explains input options, lists returned data, hints at optional flags, and then provides sibling routing and cost note. It is front-loaded and logically ordered, though slightly long; 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?

Given 11 parameters, full schema coverage, and no output schema, the description does a good job of summarizing what the tool returns (metadata, parentage, etc.) and when to use it. It does not discuss error handling or pagination, but those are minor gaps for a read-only drill-down tool with this level of schema documentation.

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 description coverage is 100%, so the schema already documents all 11 parameters thoroughly. The description adds context about how to combine parameters (e.g., 'pass the point result's stack loc_ids together') and mentions flags like include_hierarchy and include_references, but does not replicate or extend parameter meanings beyond the schema. This meets the baseline for high coverage.

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 states a specific action ('drill-down tool') on a specific resource (loc_ids), lists the exact data returned (metadata, parentage, shape status, vintage/lifecycle, child counts), and explicitly distinguishes itself from siblings like resolve_point, get_geometry, and compare_geographies. This makes the tool's purpose unambiguous and distinct.

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 gives clear when-to-use guidance: 'This is where detailed chain explanation belongs; resolve_point intentionally stays compact,' and explicitly routes to alternatives: 'For exact polygons use get_geometry, and for overlap or successor analysis use compare_geographies.' It also explains input modes (single loc_id vs. stack together), satisfying both selection and invocation context.

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