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

Beyond the 'destructiveHint' annotation, the description discloses critical behavioral traits: it only updates 'the fields given' (partial updates), and guarantees that 'meanings and practice progress are not touched.' This operational context is crucial for agent planning.

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 definition is dense due to the complexity of the word object (14 parameters), but it is highly structured and efficient. It front-loads the list of editable fields and immediately follows up with the operational constraints and limitations.

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 large number of parameters and the complex nature of the data structure (nested expressions/collocations), this description provides all the necessary behavioral boundaries and operational logic required for an AI agent to select and call the function correctly without ambiguity.

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?

Even though schema coverage is 100%, the description adds significant semantic value that the schema lacks. It explains the operational rules for specific fields, such as the implications of only updating specified parameters and how previous values are replaced.

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 identifies the action ('Changes a word') and comprehensively lists all the resources/fields that can be manipulated (headword, part of speech, level, etc.). It is specific and directly relates to editing an existing word, distinguishing it from 'add_word'.

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?

It explicitly defines when to use the tool by describing which fields are editable. Crucially, it also states a key constraint: 'A headword the notebook already has is refused,' clarifying that this tool is for modifying existing entries rather than creating new ones, providing a vital boundary against the 'add_word' sibling.

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