texture_preview

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuinely new information beyond them: the return is a PNG image rather than structured data, and there is no output schema to convey that.

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 short, front-loaded segments with the action stated first and the helper routing last. The '[INSPECT] Read-only' prefix partially duplicates the annotations, which is minor waste but not damaging.

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?

A simple read tool with full schema coverage needs little prose, and the image-output disclosure covers the main gap. However, with zero required parameters and two alternative identifiers (name/uuid), the description never clarifies that at least one identifier must be supplied, leaving a real invocation ambiguity.

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 name, uuid, and maxSize are already documented in the schema. The description adds no extra meaning about parameter interaction (e.g., whether name or uuid is required, or how maxSize affects output). 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 ('Show a texture as a PNG image'), which clearly distinguishes it from texture_details and texture_list. It stops short of an explicit contrast with texture_details, but the 'as a PNG image' framing makes the image-preview nature 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?

Names a concrete prerequisite/alternative: 'Use texture_list to find names/UUIDs.' That routes the agent correctly before invocation. It does not say when to prefer this over texture_details, so it falls just short of the top score.

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