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

Annotations already declare readOnly=false, destructive=false and idempotent=false. The description usefully adds the account quota ('a free account can track one app'), which annotations cannot convey. However, given idempotent=false it should say what happens on a repeat call (error vs duplicate) and whether the app must exist/be resolvable — the mutation semantics remain underspecified.

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?

Three short sentences, front-loaded with the action, then the parameter clarification, then the quota constraint. Nothing is padded, though the quota detail would read better attached to a usage condition rather than floating as a standalone statement.

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 2-parameter mutation with no output schema, the definition covers the essential ambiguities: scope (one country), the country format, and the account limit. Missing detail about duplicate handling is a modest gap, not a blocking one, so this sits just at the adequate-but-not-rich level rather than being incomplete.

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 0%, so the description must carry parameter meaning. It does clarify country as a two-letter storefront code, which goes beyond the regex pattern, but appId is left entirely unexplained (presumably a numeric App Store ID, but that is inferred from the pattern alone) and no guidance on where to source it.

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 ('Track an App Store app') plus a scope qualifier ('in one country'). It is distinguishable from add_tracked_keywords by the resource named, though it never explicitly contrasts with that sibling.

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 implied rather than stated: you call it to track an app, and the description adds a concrete constraint ('A free account can track one app'). There is no explicit when-not guidance, no mention of what to do if the app is already tracked, and no pointer to list_tracked_apps or find_apps to obtain the appId first.

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