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

Annotations only mark readOnlyHint true, but the description adds valuable behavioral context: it returns results only 'when approved geometry exists', includes 'N-way successor context', and mentions that 'no payment required'—implying some external cost or authorization check. It does not contradict annotations and adds nuance beyond the simple 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 four sentences, front-loaded with the purpose, then outputs, then usage context, then caveat and payment note. Every sentence adds distinct information with no filler, making it appropriately sized and structured.

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 complexity and lack of an output schema, the description covers key invocation context: when to use, what it returns, and a condition ('when approved geometry exists'). It does not explain what 'approved geometry' means or how to interpret 'N-way successor context', but it provides enough for an agent to select and call the tool appropriately.

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 baseline is 3. The description mentions 'temporal validity' in outputs, which loosely ties to as_of parameters, but it does not add specific meaning to parameters like left_loc_id, include_successors, or batch_id. The schema itself already describes each parameter clearly.

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 it is a 'Detailed relationship tool for two geographic identities' and enumerates specific outputs: 'temporal validity, N-way successor context, topology, geodesic intersection area, and directional overlap shares'. This distinguishes it from siblings like get_geometry or loc_id_info, which focus on single identities.

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?

Explicit guidance is given: 'Use this after a compact point lookup when the caller asks whether two tiers/releases really contain or overlap one another' and 'Use resolve_reference first for names or outside identifiers.' This tells the agent when to use the tool and when to use an alternative, plus the caveat that 'a point-chain seam is not proof of strict parentage.'

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