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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: it returns only file names and order, no image content, and cannot change the cover or order. This goes beyond the annotations and helps set expectations.

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?

Two sentences, front-loaded with the key purpose and output format, followed by explicit exclusions. Every sentence earns its place with zero waste.

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 simple read-only list tool with one parameter and full schema coverage, the description is nearly complete. It clearly states what is returned (file names and order) and what is not (image content, cover/order changes). The only minor gap is not describing the exact output structure, but since there is no output schema and the tool is simple, this is a small omission.

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 fully documents the single parameter (propertyId). The description doesn't add parameter-level detail beyond what the schema provides, but it does clarify the output context (gallery photos for a listing). 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 states a specific verb ('list'), a resource ('a listing's gallery photos'), and the exact scope ('display order (first = cover)'). It also distinguishes itself from sibling tools by clarifying it returns only file names and order, not image content. This is clear and unambiguous.

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 implies when to use this tool: when you need gallery photo file names and order for a listing. It explicitly states what it does NOT do (no image content, no cover/order changes), which helps an agent avoid misusing it. However, it doesn't explicitly name alternative tools for those other operations, so it falls just short of a 5.

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