market_new_apps

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real behavioral context beyond that: results are ordered newest-first, each row carries its publisher, and the `daysCovered` field qualifies index coverage so the agent knows a first-seen date is bounded by what was actually indexed. Pagination/limit behavior is still unstated.

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, zero filler, and the core identity of the tool ('apps seen on a top chart for the first time') is front-loaded before the coverage caveat. Nothing is restated from the name or schema.

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?

With no output schema, the description carries the return-shape burden and does disclose the key fields (app, publisher, first-seen ordering) plus the meaning of daysCovered. It stops short of saying how many rows come back by default or how limit/days interact, which matters for a 3-optional-param feed but is not fatal.

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% — days (up to 30), limit (up to 200) and country are all documented in the schema. The description mentions `daysCovered`, which is an output field rather than a parameter, and adds no syntax or defaulting detail for the three inputs. 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?

The description states a specific resource and scope: apps appearing on a top chart for the first time, with the publisher attached. That is clearly distinct from a snapshot tool like market_charts or a rank-movement tool like market_movers, though it never names a sibling explicitly to anchor the distinction.

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?

There is no when-to-use or when-not-to-use guidance, and no alternative is named despite many close siblings (market_charts, market_movers, get_chart_movers, get_featuring). The agent must infer from the phrase 'first time' that this is a new-entry discovery feed rather than a chart ranking feed.

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