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

The readOnlyHint annotation already signals a safe read operation. The description adds valuable context beyond that: it is 'fast' and 'shape-only' indicating no actual geometry is returned, explicitly states it does not resolve points or identity relationships, and notes 'No payment required.' This gives the agent a clear picture of behavioral limitations and costs.

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 three concise sentences that front-load the core action and outcome. Every sentence contributes useful information (what it does, what it does not do, when to use it, payment status) without redundancy or fluff.

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's simple preflight nature, the description covers what it returns ('whether... has reusable geometry and its geometry vintage'), what it excludes, and when to use it. No output schema exists, but the return content is summarized sufficiently for an agent to decide invocation and interpret the result.

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 parameters are already well-documented. The description adds some context by clarifying the loc_id/loc_ids relationship as 'one or a bounded list,' but it does not significantly go beyond the schema details. 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 is a 'Fast shape-only preflight' for one or more loc_ids, and specifies what it reports (geometry availability and vintage). This clearly distinguishes it from get_geometry (which retrieves geometry) and other sibling tools by emphasizing it is a preflight check.

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 explicitly says 'Use before get_geometry or an export,' providing direct guidance on when to use this tool relative to alternatives. It also notes what the tool does NOT do ('does not resolve points or explain identity relationships'), which helps exclude inappropriate use cases.

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