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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description goes beyond them by disclosing the return shape (meaning, example, nickname references, glossary link), the corpus size (~276 terms), and the fuzzy fallback of up to three close matches when no exact hit exists — behavior an agent cannot see anywhere else since there is no output schema.

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 tight sentences: trigger first, then parameter note, then return behavior — well front-loaded with no filler. The inline 'term: the word or phrase as written.' line partially duplicates the schema's parameter description, which is the only wasted element.

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 single-parameter lookup with no output schema, the description supplies everything needed: when to call it, what to pass, what comes back, and what happens on a miss. Nothing material is missing for correct invocation.

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% and there is only one parameter, so the baseline is already high; the description adds the useful instruction that the term should be passed 'as written' and illustrates the range of inputs (abbreviations, nicknames, jargon) the parameter accepts. This is modest but real value beyond the schema's 'The term, abbreviation or nickname.'

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 names a specific verb and resource ('explain a watch or dealer term, abbreviation or nickname') and enumerates concrete examples (BNIB, LNIB, full set, hesalite, grey market, Hulk, Pepsi) that pin down the domain precisely. None of the sibling tools do glossary lookup, so the tool is easily distinguished from look_up_watch_reference or find_watch_by_name.

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 opening 'Use when someone asks what a ... term ... means' gives an explicit trigger condition, which is stronger than most definitions. It stops short of naming exclusions or the adjacent case (a model/reference number should go to look_up_watch_reference rather than here), so the agent must infer that boundary.

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