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

No annotations are provided, so the description carries the full burden. It discloses 'Read-only' and adds a behavioral nuance: 'Access dates are injected at call time — never hardcoded.' This goes beyond the function name and covers safety expectations. It doesn't describe error behavior or return structure, but for a simple citation tool this is adequate.

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 three sentences, each earning its place: main function, a key behavioral note, and usage guidance with alternative. No fluff or repetition. Front-loaded with 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 tool's low complexity (2 required params, no output schema, no annotations), the description covers purpose, usage, alternative, and safety. It doesn't explicitly state whether all three citation formats are returned together or how errors are handled, but the guidance is sufficient for an agent to invoke it correctly in most cases.

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%: both 'term' and 'context' are described in the schema. The description adds no new parameter-level details beyond what the schema provides. It mentions 'Arco term' but doesn't clarify parameter syntax. Baseline 3 is appropriate given high schema coverage.

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 opens with a specific verb and resource: 'Returns citation-ready references for a Lexicon term in Chicago, MLA, and BibTeX formats.' It distinguishes itself from siblings by naming the alternative 'get_sources' for a different need (list of reading references vs formatted citation).

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?

Explicitly states when to use: 'Use this when producing academic papers, blog posts, or any content that requires a formatted reference to an Arco term.' It also provides a clear alternative: 'Use get_sources instead when you need a list of reading references rather than a formatted citation.'

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