find_token_by_color

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds two genuinely useful behavioral facts beyond that: matching is EXACT (no fuzzy or nearest-color fallback) and the result may be plural ('token(s)'), so the caller should expect zero-to-many matches rather than a single object.

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?

One short sentence, front-loaded with the 'Reverse lookup' framing and then the concrete constraint, with no filler or redundant restatement of the tool name.

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?

With an output schema present and only one required parameter, the description does not need to explain return shape, and it correctly signals exactness and possible multiplicity. However, for a color-input tool the absence of hex format guidance (prefix, digit count, casing) is the one gap that could cause a failed or empty call.

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 0% and the single hex_color parameter has only a title, so the description must carry the format burden. It does confirm the value is a hex color and that matching is exact, but it omits the concrete format details an agent needs: leading '#', 3- vs 6-digit forms, alpha channel support, and case sensitivity.

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 gives a specific verb-plus-resource ('Find token(s)') and frames it as a 'Reverse lookup' on an exact hex color, which clearly separates it from forward-looking siblings like add_token, set_token, or get_token_siblings. It stops short of naming an adjacent search/list tool (e.g. list_tokens) that an agent might otherwise confuse it with.

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 implied rather than stated: the agent can infer this is the tool for 'I have a color, what token is it?' and that it is not for listing or editing tokens. There is no explicit when-not guidance, no mention of alternatives when the color is not an exact match, and no note on what to do if nothing is found.

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