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

With no annotations provided, the description bears the full burden of behavioral disclosure. It mentions 'auto-add' and 'browser-based' but does not explain how the tool operates, whether it modifies existing text, what reading aids are added (furigana, hiragana, etc.), or any side effects. This leaves significant ambiguity for agents deciding on invocation.

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?

The description is two short sentences with no filler. The first sentence conveys the core action, and the second adds a useful context flag (browser-based). Every word earns its place, and the structure front-loads the most important 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?

Given the lack of an output schema and the absence of parameters, the description does not fully explain what the user/agent should expect from the tool. It does not specify input sources, output format, or how the browser-based behavior manifests. Despite its simplicity, the tool is under-specified for an agent to invoke without further clarification.

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?

The input schema has zero parameters and 100% schema coverage (vacuously). Per the rules, the baseline for 0 params is 4, and the description adds a relevant semantic detail: 'by grade level' implies a configurable level selection, even if not represented as a schema parameter. This gives the agent some idea of what to expect in the browser interface.

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 clearly states the tool's function: 'Auto-add reading aids to kanji by grade level.' This uses a specific verb ('add'), a resource ('kanji'), and a distinctive scope ('by grade level'), which differentiates it from the many unrelated sibling tools. The title 'Furigana Adder' is reinforced with meaningful elaboration.

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?

No guidance is given on when to use this tool or when to prefer an alternative. The phrase 'Browser-based tool' gives a vague usage context but does not explain prerequisites, input requirements, or exclusions. There is no mention of scenarios for which this tool is more suitable than others.

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