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

Annotations already declare readOnlyHint and non-destructive behavior. The description adds useful behavioral context beyond that, including fragment matching and normalization ('ignores case and diacritics'). It does not contradict the read-only annotation and meaningfully complements it.

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?

Three short sentences deliver purpose, matching behavior, and a usage directive, with no filler or repetition. The most important information is front-loaded, and every sentence earns its place.

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 read-only search tool with annotations covering safety, the description is nearly complete. It lacks an explicit description of the result shape, which would be useful since there is no output schema, but the usage guidance and search semantics give an agent enough to invoke it correctly.

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 schema documents language parameters but leaves query and limit without descriptions. The description clarifies that query is a fragment of either term or translation, which is helpful, but it doesn't explain the limit parameter's semantics or how language filtering interacts with the search. With 50% schema coverage, the description only partially compensates.

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 verb ('Finds'), resource ('words in the user's NextLang dictionaries'), and search criteria ('fragment of the term or its translation'). It is clearly distinct from sibling tools like list_decks or list_due_words, and the search scope is unambiguous.

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?

The instruction 'Call this before telling the user a word is not in their vocabulary' provides a clear, actionable trigger for use. It doesn't discuss when-not usage or alternatives, but as the only search tool among siblings, this is acceptable.

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