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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), but the description adds real value beyond them: 'Reading does not download or import images' clarifies the absence of side effects, and the prompt-injection warning about public text is a meaningful behavioral note not captured by any structured field.

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?

Three tight sentences, front-loaded with the action and resource, then the two behavioral notes. No filler, though the injection warning is somewhat boilerplate-heavy for a simple list tool.

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 single-parameter read-only list tool with full annotation coverage and no output schema, the description is nearly complete: it names the return content (image URLs) and warns about the nature of the embedded text. Only the relationship to list_feature_comment_images is unaddressed.

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?

Only one parameter, and schema description coverage is 100% – the schema already documents feature_id including its source ('From list_features or search_features'). The description adds no syntax or format detail, so the baseline 3 applies.

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?

States a specific verb and resource: 'List image URLs currently attached to this request.' The scope phrase 'attached to this request' implicitly distinguishes it from the sibling list_feature_comment_images, though it never names that alternative. Clear enough for an agent to understand the target resource.

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?

Usage is only implied by the scoping phrase 'attached to this request'; there is no explicit when-to-use guidance and no named alternative such as list_feature_comment_images. The agent can infer the tool is for request-level images, but routing versus the comment-images sibling is left to inference.

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