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

With no annotations, the description carries the full burden; it does disclose the algorithm and the return artifact, which is useful. However it says nothing about whether the operation mutates state, whether the result is stored or ephemeral, how failures (unreachable URL, oversized image) surface, or any cost/rate considerations.

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 tight sentences with zero filler, front-loading the action and following with the output format. Nothing needs trimming.

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?

No output schema exists, and the description compensates by naming both return artifacts (hex codes and a .gpl file). Combined with the fully documented schema, an agent has everything needed to call it correctly.

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 coverage is 100% with three fully documented parameters, including defaults, bounds, and the URL-vs-base64 fallback, so the schema does the heavy lifting. The description adds no parameter-level meaning beyond noting the output palette format.

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 ('Pull the main colours out of an image') and names the algorithm (median cut) plus the output artifact (hex codes and a .gpl palette). It is clearly distinct from remap_palette and list_palettes, though it never explicitly contrasts itself with those siblings.

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: the tool is for extracting a new palette rather than applying an existing one. There is no explicit statement of when to choose this over remap_palette or how it relates to list_palettes, and no preconditions are given.

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