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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds nothing behavioral beyond that — no ordering, result caps, or pagination guidance for what could be a large set of 'new' apps. With rich annotations the bar is lower, so this is minimum-viable rather than deficient.

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 short sentences with no filler; the scoping definition is front-loaded and the usage cue follows immediately. Every clause earns its place.

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 two-parameter, read-only, fully documented schema with no output schema, the description supplies enough to call the tool correctly. It could be marginally richer about the shape of results (e.g., ordering or limits), but nothing essential is missing.

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% and the enum values (abi/aii/aei) are already explained in the schema, so the schema carries the parameter burden. The description only restates the temporal window ('after a given hour') without adding format or boundary semantics beyond the schema's ISO-hour note. 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?

The description states a specific resource and scope: Arc apps 'first seen in an index after a given hour.' This distinguishes it from the broader arc_apps sibling, though it never names that sibling or arc_app_history explicitly. An agent can infer the difference from 'first seen ... after a given hour' alone.

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?

'Use this when asked what is new on Arc' gives a clear triggering context for invocation. It stops short of naming alternatives (arc_apps, arc_app_history) or stating when not to use it, but the usage context is unambiguous.

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