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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description need not re-argue safety. It adds real context beyond them: result ordering by soonest availability, the fixed 60-minute session length, the deliberate omission of meeting links, and a coarse (privacy-limited) host card. It stops short of stating result caps or that availability is live/non-idempotent.

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?

A single dense sentence, front-loaded with the resource and the ordering rule, followed by the returned fields and the no-meeting-link caveat. Every clause carries information, though the return-field list and the constraint could be split for easier scanning.

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 no output schema, the description correctly takes on the burden of describing the return shape and does so field by field. The remaining gaps are secondary: no pagination or result-count limit, no statement that both parameters are optional, and no note that availability is time-sensitive.

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 description coverage is 100% and the schema itself explains the topic enum and the timezone fallback-to-UTC behaviour, so the description is not required to carry parameter meaning. It adds nothing beyond the schema for either parameter, which is the baseline-3 case rather than a gap.

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+resource and scope: members of the buddy network the person 'could book a 60-minute mock interview with now'. It then enumerates exactly what each result carries (handle, coarse card, topics, next open slot, rating), which is enough to distinguish it from sibling list/book/slots tools without opening a schema.

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?

Usage is implied rather than stated: 'could book ... now, soonest available first' signals this is the discovery step before buddy_mock_book, but no sibling is named and no exclusions are given. Nothing says when to prefer buddy_mock_slots or buddy_mock_list instead, and any membership prerequisite (e.g. buddy_join) is left to inference.

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