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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely new behavioral context beyond them: that results are permission-scoped and that admin keys additionally surface inactive sub-calendars, which is exactly the kind of hidden filtering behavior an agent must know. It stops short of describing pagination mechanics or rate limits.

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?

Two short sentences with the resource definition front-loaded, followed by the one non-obvious behavioral caveat. The trailing endpoint reference is compact and adds a concrete anchor without padding.

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 four-optional-parameter, paginated list tool with no output schema, the definition covers the resource, its permission-scoped visibility, and the inactive caveat. Pagination and return-field shape are left to the schema, which is acceptable, though a hint about what a sub-calendar object contains would close the remaining gap.

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%, so limit, offset, name_contains and include_inactive are fully documented in the schema and the baseline is 3. The description adds no syntax or format detail for any parameter; its mention of inactive entries only loosely reinforces the include_inactive flag.

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 (List) and resource (sub-calendars) and adds a clarifying gloss ('the colored lanes that events belong to, such as people, rooms or resources') that makes the concept unambiguous. The plural verb naturally separates it from the sibling teamup_get_subcalendar, and the endpoint line confirms the resource path.

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 by the name rather than stated: there is no explicit 'use this when you need X, use get_subcalendar when you need one item'. The permission note ('A key with admin permission also sees inactive ones') is the only conditional guidance, and it describes visibility rather than when to choose this tool.

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