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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description contributes beyond that by disclosing the return payload shape ('list metadata and the ordered routes'), which matters since there is no output schema. It omits error behavior for an unknown slug, which keeps it short of a 5.

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 no filler; the action and lookup key are front-loaded and the return content follows immediately. Nothing could be removed without losing information.

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 one-parameter read tool with no output schema, the description covers what it fetches and roughly what comes back, and annotations cover the safety profile. The only real gap is what happens on a bad or missing slug.

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% and the single parameter already documents both its origin (browse_runlists) and the URL format. The description's 'by slug' phrase merely restates the parameter name, adding no new semantics, so the baseline 3 applies.

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 ('Fetch a Skamper run list') plus the lookup key ('by slug'), and adds scope by noting it returns metadata and the ordered routes inside. It separates itself from browse_runlists only implicitly, since the sibling is never named as the contrasting tool.

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 only implied: the tool is clearly the detail-lookup counterpart to a listing tool, but the description never says when to prefer this over browse_runlists or search_routes. The slug provenance hint lives in the schema, not the description.

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