Extract and Name Colours from an Image

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

The description discloses important behavioral traits beyond the readOnlyHint annotation: 'image is never stored — processed in memory only' (privacy guarantee), technical details (K-means++, Bradford chromatic adaptation), and a structured list of output fields (archive name, cultural story, RAL standard, WCAG data). No contradiction with annotations.

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?

The description is a single paragraph of four sentences, efficiently front-loading the main action. Every sentence adds value (purpose, method, output, use cases, data handling). Slight improvement could be made with bullet points for readability, but current structure is good.

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?

Given that an output schema exists (context signal), the description appropriately summarizes output fields. It covers purpose, use cases, behavioral detail, and parameter limitations. Could be slightly more detailed about the matching process or edge cases, but overall complete enough.

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%, so the baseline is 3. The description adds algorithm context but does not elaborate on individual parameter values, constraints, or format beyond what the schema already provides. The max n_colours=5 is stated in schema and reinforced in description, adding minimal value.

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 uses specific verbs ('upload', 'extract', 'match') and clearly identifies the resource ('image'). It distinguishes from sibling tools by mentioning unique features: named archive entries with cultural provenance, Bradford chromatic adaptation, WCAG data. No ambiguity.

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 lists concrete use cases ('product photography, interior photos, artwork, brand assets, and mood boards'), providing clear context. However, it does not explicitly state when not to use this tool or name alternative tools for different needs.

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