download_icon

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

With no annotations provided, the description carries full burden. It discloses format support (SVG/PNG) and API limitations (public domain only for free access), which are useful behavioral traits. However, it lacks details on permissions, rate limits, or error handling, leaving gaps for a mutation-like download operation.

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 front-loaded with the core purpose, followed by key features and a critical note, all in three concise sentences with zero wasted words. Each sentence adds distinct value, making it highly efficient.

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?

For a tool with 5 parameters, no annotations, and no output schema, the description is moderately complete. It covers purpose, formats, and API limitations, but lacks details on return values, error cases, or authentication needs, which are important given the download operation's complexity.

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 fully documents all 5 parameters. The description adds minimal value beyond the schema by mentioning 'custom color and size options' and format support, but doesn't provide additional syntax or constraints. Baseline 3 is appropriate as the schema does the heavy lifting.

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 clearly states the verb 'download' and resource 'icon' with custom options, making the purpose evident. It distinguishes from siblings like 'get_icon' by specifying download functionality. However, it doesn't explicitly contrast with all siblings, keeping it at 4 rather than 5.

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 implies usage through the mention of 'custom color and size options' and format support, but provides no explicit guidance on when to use this tool versus alternatives like 'get_icon' or 'search_icons'. The note about free API limitations offers some context but not sibling differentiation.

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