make_icon

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

Annotations already establish it is non-destructive (destructiveHint=false) but does perform work with open-world lookups (openWorldHint=true). The description adds genuinely useful behavioral context beyond that: it produces a preview and writes a file artifact, and the schema-supplied defaults (colour, background) are complemented by the note that defaults are auto-chosen for readability and brand colour. No permission or rate-limit detail, but little is expected here.

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 sentences with zero filler, and the core purpose is front-loaded ahead of the output/usage note. Every clause carries information an agent needs.

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?

There is no output schema, so the description usefully documents what comes back (a preview and a file path) and how to consume it. For a single-purpose asset-generation tool this is nearly complete; only minor details such as output image format or overwrite behavior are absent.

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 the schema already documents every parameter including the icon syntax, scale range, style values, and colour/background formats. The description only restates the input categories in prose and adds no syntax or format detail beyond what the schema provides; baseline 3 is correct.

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 ('Make a key image') plus the four input modes it supports (text, emoji, brand logo, generic symbol). This clearly separates it from sibling find_icons, which only looks up icon names rather than producing the image.

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 explicitly routes the agent downstream: the returned file path is meant to be passed as `image` to set_key / update_key / add_child, and it points at find_icons for discovering icon names. It stops short of stating when this tool is unnecessary (e.g. when an image already exists), so it is clear context rather than full when/when-not guidance.

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