Zrd Summary

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

With no annotations, the description carries full burden but does disclose two useful traits: it "streams" (rather than loading the whole file) and returns "bounded" aggregates. It does not describe what the aggregate fields are, permission requirements, or error behavior on a missing/invalid ZRD.

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?

A single front-loaded sentence with no waste. It is efficient, though "bounded aggregate metadata" is slightly abstract and could be swapped for one concrete clause at no length cost.

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?

There is no output schema, yet the description never says what "aggregate metadata" contains, so an agent cannot know the return shape before calling. Combined with no annotations, this leaves a meaningful gap for an analysis-style tool.

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 all four parameters (filter, filePath, maxRaysToScan, maxSegmentsToScan) are already documented in the schema. The description adds no additional syntax, format, or interaction detail beyond that baseline.

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 gives a specific verb ("Stream") and resource ("existing ZRD") plus the return shape ("aggregate metadata"), which distinguishes it somewhat from the raw-ray sibling zemax_zrd_read. However, it never names zemax_zrd_read or explicitly contrasts summary vs full read, so sibling differentiation is only implicit.

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?

There is no when-to-use guidance, no prerequisite statement, and no mention of the obvious alternative zemax_zrd_read. The agent must infer from the tool name that this is the summarization path rather than the full-read path.

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