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

The annotations already declare that this is a read-only, idempotent, open-world lookup, so the description does not need to repeat those safety traits. It adds useful context by naming the data source (Free Dictionary API via Wiktionary), noting that multiple meanings and nuances are covered, and disclosing a cost of 1 credit.

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 short, front-loaded with the core action and return content, and uses the remaining space for source attribution and cost. Every sentence carries relevant 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?

For a simple one-parameter lookup with annotations and no output schema, the description is largely complete: it says what content is returned and where it comes from. A minor gap is that it does not mention behavior when no definition is found.

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 100%, so the single parameter is already well documented as the English word to define. The description reinforces that it is an English word but adds no new syntax, constraints, or interpretation beyond the schema.

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 action and resource: looking up dictionary definitions, parts of speech, and usage examples for an English word. It is clear what the tool returns, but it does not explicitly differentiate itself from close siblings such as synonyms_for_word or word_pronunciation.

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 explicit guidance on when to use this tool versus alternatives like synonyms_for_word, words_meaning_like, or word_pronunciation. The scope is implied by the phrase 'dictionary definition,' but no alternatives or exclusions are named.

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