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

Annotations already establish this as a non-destructive, open-world read, so the description's real contribution is the behavioral detail: the fixed 60-minute slot length, a default 30-day window capped at 62 days, and the fact that no meeting link is ever returned. That 'never includes a meeting link' line is genuinely useful, implying booking is required before a link exists. It does not address the idempotentHint=false flag, so the agent gets no hint about whether repeated calls may return different slot sets as availability changes.

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 with the resource and scope up front, then the window constraint, then the meeting-link caveat. Nothing is padded or repeated, though the phrase 'by handle' is slightly awkwardly embedded mid-clause.

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?

There is no output schema, and the description does cover the essential shape of the result: slots with starts_at values plus the host's topics, and the absence of meeting links. It does not say whether results are sorted, whether the list can be empty or truncated, or what the caller should do if no slots fall in the window, which for a listing tool an agent will likely want to know before falling back to widening from/to.

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%, so the baseline is 3. The description does add real meaning on top: it clarifies that starts_at is the instant to book rather than a display string, and it states the 62-day maximum window, which the schema's own parameter descriptions do not mention (the schema only gives the 30-day default). Those are increments, not a rewrite of what the schema already says.

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: it lists the open 60-minute mock-interview slots of one host, identified by handle, along with that host's offered topics. That is concrete enough to separate it from buddy_mock_hosts (which finds hosts) and buddy_mock_book (which reserves a slot), though it never names those siblings outright.

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 usage context is implied rather than stated: the note that each starts_at is 'the exact RFC 3339 instant to book' points the agent toward buddy_mock_book as the follow-on action, but there is no explicit 'use this when' statement and no named alternative. No exclusions or prerequisites are given, such as whether the caller must be the host.

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