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

Annotations already declare readOnlyHint=true and idempotentHint=true, so safety is covered. The description adds behavioral detail by disclosing that it returns two categories of platforms (integrated vs site) and exactly what fields are returned, giving the agent a clear picture of the output beyond the structured metadata.

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 dense but efficiently packed with relevant detail. The primary action and resource are front-loaded, followed by the output fields and usage hint. Every sentence earns its place; there is no fluff or repetition.

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 there is no output schema, the description compensates by enumerating the returned fields (slug, availability, fee, integrated/site status). It also covers the chain_id options and how to consume the result. Minor gaps like the exact data type of 'live availability' are acceptable for a read-only list tool.

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?

The schema already fully documents chain_id (100% coverage), so baseline is 3. The description adds context by restating the allowed values and clarifying that the chain_id selects which Arc network to list launchers for, reinforcing the parameter's role in the tool's purpose. This is helpful but not essential.

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 'List' and the resource 'launcher platforms on Circle's Arc', and specifies the exact information returned (slug, live availability, fee, integrated vs site). It distinguishes itself from sibling tools like launchpad_launch_token by focusing on enumeration, making its purpose unmistakable.

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 tells the agent what to do with the output ('Pass the slugs as `platforms` to launchpad_launch_token'), implicitly defining when to use this tool (before a cross-launch). It also names the valid chain_id values. It does not explicitly contrast with alternatives like launchpad_list_tokens, but the purpose is clear enough to route correctly.

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