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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds real context beyond that: the result is prose meant to be rephrased in the agent's own words, and replies identify the topic under a `guide` field, which implies a fallback workflow — useful behavioral signal.

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 dense sentences, front-loaded with the purpose and the topic list, then the return contract. No filler; the topic list duplicates the enum but does so compactly.

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?

One required enum parameter, full schema coverage and an output schema mean return values and parameter details need no restating. The description covers what an agent needs to call it and phrase the answer, with only the omitted whats_new topic as a minor gap already handled by the enum.

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 the enum descriptions in the schema are richer than the prose (the description lists eight topics and omits whats_new, which only the enum documents). The description adds the mapping between replies and topic selection but no semantics beyond what the schema already provides, so baseline 3 applies.

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?

States a specific verb and resource ("Explains one part of JooVoice") and narrows it to an enumerated set of topics, so the agent knows it is a topic-scoped knowledge lookup. It implies the fallback role ("when the owner asks and a reply doesn't say") but never names the sibling it is not, e.g. answer_questions.

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?

Gives a clear triggering condition: use it to answer the owner when an existing reply doesn't cover the question. It stops short of explicit exclusions or naming alternatives among the many siblings (answer_questions, check_account, read_settings), leaving the boundary implicit.

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