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

The annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior, so safety disclosure is not the description's burden. The description usefully adds what the payload contains (definition plus why it matters to an investor) and that omission of term degrades to a list. It says nothing about behavior for an unknown or ambiguous term, or how many entries a bare list returns.

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, front-loaded with the resource and its value, then the mode-switch rule, then the usage trigger. No filler; the parenthetical examples earn their place by disambiguating the glossary domain. The opening is a noun phrase rather than a verb, which is slightly weaker but not costly.

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 only two optional parameters, no nested objects, no output schema, and rich annotations, the definition covers what an agent needs to call it: what comes back, how to list versus look up, and when to reach for it. Missing are edge-case behaviors (unknown term, empty query result, result cap), which keep it from a 5.

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 both parameters are already documented, including "omit to list terms" and the containment semantics of query. The description restates that omission triggers listing/searching but adds no format, matching, or fallback detail beyond the schema. Baseline 3 is appropriate when the schema carries the parameter meaning.

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 the resource (AI investing glossary definitions) with concrete example entries (neocloud, hyperscaler, PPA) and states what a lookup returns: a definition plus investor relevance. It also clarifies that the same tool doubles as a listing/search surface when no term is supplied. It does not explicitly distinguish itself from the nearest sibling, get_methodology, but the resource is specific enough to be 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?

"Use for 'what is X' questions" gives a concrete trigger condition, and "Lists or searches terms when term is omitted" tells the agent how to switch modes. There are no explicit exclusions or named alternatives, so the agent must infer that methodology/deeper documentation lives elsewhere.

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