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

Annotations already declare the full safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds genuinely new context beyond them: the 30-day data window and the cost of 1 credit per call, which is exactly the kind of rate/cost disclosure an agent needs before calling.

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 short sentences with zero filler, front-loading what the tool returns and its time horizon before the cost note. Nothing could be removed without losing information.

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?

This is a simple one-parameter read with no output schema and a complete annotation set, so the description does not need to explain return values. It covers scope and cost adequately; the only real gap is behavior when the keyword is unknown or untracked.

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% for the single required "keyword" parameter, so the description must compensate. It does so only partially: "a tracked keyword" hints that the value must match an existing tracked keyword rather than an arbitrary string, but says nothing about format, case sensitivity, or how to discover valid values.

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 granularity ("Daily mention history") plus a scope limit ("up to 30 days") for a named entity ("a tracked keyword"). This is clearly distinguishable from siblings like estimate_cost or rising_keywords, though it never explicitly contrasts itself with them.

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 guidance on when to reach for this tool versus alternatives such as rising_keywords or rising_creators, nor any stated preconditions. The phrase "tracked keyword" faintly implies the keyword must already be tracked, but that prerequisite is never spelled out, and no exclusions are given.

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