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

The annotation readOnlyHint=true is already present, and the description reinforces it without contradiction. It adds substantial behavioral context beyond the annotation: the 'lightweight default' that avoids scanning data rows or polygon coordinates, the 'strict stored parentage' and 'strict same-release ancestor chain' with no invented edges across mixed releases, and the explicit non-substitution of successors. These details give the agent a precise picture of the tool's side effects and guarantees.

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 concise and tightly packed, with no wasted words. It front-loads the core purpose, then details the default output, then flag behaviors, then historical handling, then alternative tools, and finally the payment note. Each sentence earns its place, and the structure flows logically from what the tool is to how to use it and when not to.

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 tool with 11 parameters and no output schema, the description covers all essential aspects: what it does, what it returns by default, which flags alter behavior, edge cases (historical, mixed releases), and alternatives. It does not describe the return format, but since there is no output schema, the burden shifts to the description to convey content, which it does thoroughly. The proxy for completeness is high.

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 every parameter already has a description. The tool description adds value by explaining the purpose of two key flags: include_hierarchy for 'strict same-release ancestor chain' and include_references for 'exact external or cross-family connections', plus the bounded nature of loc_ids. This goes beyond the schema's terse descriptions, though it doesn't elaborate on all 11 parameters. Given the high coverage, the description's extra context pushes it above the baseline of 3.

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 verb ('navigation and enrichment tool') and resource ('one loc_id or a bounded loc_ids array'), and enumerates the exact default output fields (identity, parentage, shape status, lifecycle, data-pack coverage, geometry families, next calls). It also explicitly contrasts with siblings ('Use get_data for rows, get_geometry for polygons'), making differentiation clear without needing to inspect other schemas.

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 provides explicit when-to-use guidance by naming three alternative tools (get_data, get_geometry, compare_geographies) and what each is for. It also includes important behavioral caveats: historical records are returned as requested, successors are never substituted automatically, and the loc_ids array is bounded with a configurable cap. This leaves no ambiguity about when to call this tool versus its siblings.

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