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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that: daily App Store listing checks, per-country comparison of search positions, and hard plan quotas (3 Free / 10 Pro / 25 Studio per app). It does not say what happens when the quota is exceeded, which keeps it from 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?

Three short sentences, front-loaded with the action, followed by the downstream behavior and the quota constraint. No filler and nothing repeated from the title.

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 mutation with no output schema and full annotation coverage, the description supplies the missing context an agent needs: the prerequisite relationship between the two ids, the recurring background behavior, and the plan limits. Only the failure mode at quota exhaustion is unaddressed.

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%, so both parameters are already documented, including that competitor_id accepts an id or an apps.apple.com link. The description adds only the framing that app_id refers to the user's own tracked app; baseline 3 is appropriate.

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: adds an iOS app as a competitor of one of the user's tracked apps. This clearly separates it from untrack_competitor (the inverse) and track_app (which tracks the user's own app).

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 phrase 'of one of the user's tracked apps' implies the prerequisite that the target app must already be tracked, but there is no explicit when-to-use guidance, no mention of untrack_competitor as the alternative, and no pointer to get_my_apps for finding app_id.

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