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

With no annotations, the description carries the full burden and does real work: it discloses a 100-keyword per-call cap, a plan-level quota, and that an over-limit batch is rejected atomically rather than partially applied. That last detail is exactly the kind of consequence an agent cannot infer. It omits duplicate-keyword handling, idempotency, and whether adding an already-tracked keyword fails or is a no-op.

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 tightly packed sentences, front-loaded with the core action and followed by the constraint. The 'measure rank, popularity and difficulty' clause is value framing rather than invocation guidance, the only mildly expendable sentence.

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?

Quota and atomicity are covered, which is the most important behavior for a mutating tool with no annotations. But with no output schema either, the description says nothing about what comes back (created records, async job, updated usage counters) or how duplicates are treated, leaving gaps an agent needs before calling.

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 only 33%: appId is documented in the schema, but 'store' has no description and its two-letter country-code format is only implicit in the regex pattern, and the keywords items carry length bounds but no meaning. The description reinforces the 100-item ceiling but adds nothing about store semantics or keyword normalization rules.

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 ... keywords for an app in a store') plus the measurable outcome (rank, popularity, difficulty), which clearly separates it from read-side siblings like get_app_keywords or get_keyword_suggestions. It never names a sibling explicitly, so it stops short of a 5.

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 use this when you want to start tracking keywords. The description adds the free-plan ceiling (10) and the rejection behavior of over-limit batches, which is useful eligibility context, but it gives no explicit when-to-use versus add_app/refresh_app_keywords and never states the prerequisite of resolving appId via list_apps.

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