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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world scope, so safety is covered. The description adds the meaningful traits of daily granularity and single-keyword scope, but says nothing about how far back history goes, pagination, or result shape — and there is no output schema to fall back on.

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?

A single eight-word sentence with no filler and the noun phrase front-loaded. Efficiency is good, though the extreme brevity leaves obvious gaps rather than trading off against them.

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 one-parameter read tool with annotations and no output schema, the definition is minimally sufficient but omits what the caller actually gets: the shape of the history series (date/rank pairs?), the default lookback window, and whether the series can be time-bounded.

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?

Only one parameter (keywordId) and schema description coverage is 0%, so the schema provides no meaning at all. 'One tracked keyword' is the sole clue that the id refers to a tracked keyword listing rather than a raw keyword string, which is thin but non-zero compensation.

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+resource ('Daily rank history') and scopes it to 'one tracked keyword', which separates it from the app-oriented siblings like get_app_ranks and get_rating_history. It never names a sibling explicitly, so differentiation is inferred rather than stated.

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 / when-not-to-use guidance beyond the word 'tracked', which only faintly implies the keyword must first exist via add_tracked_keywords. No alternative (e.g. get_app_ranks for app-level ranks) is mentioned, and no date-range or default-period expectations are set.

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