Define a Word

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, so the tool is safe. The description adds value by detailing return components and identifying the API source ('Free Dictionary API'). It does not contradict annotations. No additional behavioral traits (e.g., rate limits) are disclosed, but the annotations cover the essential safety profile.

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 a single sentence that efficiently communicates the tool's purpose and key features. It is front-loaded with the main action and lists components concisely. No redundancy or unnecessary words.

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?

With an output schema present, the description need not detail return values; it already lists components. It covers the main use case (defining a word) and language support. Minor gaps: no mention of error handling, word length limits, or behavior for unsupported characters, but these are not critical for a straightforward lookup tool.

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 coverage is 100% with parameter descriptions. The description reiterates supported languages and provides example words, but does not add significant meaning beyond the schema. Baseline 3 applies as the schema already does the heavy lifting.

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 purpose: 'Get word definition' and lists specific components (phonetic pronunciation, part of speech, examples, synonyms, antonyms, audio URL). It distinguishes from siblings like 'language.dictionary.words' by specifying definition retrieval. The verb 'Get' + resource 'word definition' is specific and 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 description implies usage context by listing supported languages but does not explicitly explain when to use this tool versus alternatives like 'language.dictionary.words'. No exclusion criteria or prerequisites are mentioned. The guidance is adequate for a simple lookup but lacks explicit when-to-use/not-to-use instructions.

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