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

Annotations already flag destructiveHint=true, idempotentHint=false and openWorldHint=true, so the safety profile is covered structurally. The description adds real behavioral context beyond that: the operation replaces the whole schedule, an empty list wipes it, and existing dated overrides survive. It omits error/validation behavior and any return information.

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 tight sentences with the replacement scope front-loaded, followed by format/time-zone detail and the override caveat. Every clause carries information an agent needs; nothing is redundant with the title.

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 single-parameter, nested-array mutation with no output schema and destructive annotations, the description covers the key unknowns: replacement semantics, clearing behavior, time-zone basis, and preservation of overrides. Remaining gaps (overlap/conflict handling, what the response looks like) are minor for this complexity level.

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?

Top-level schema coverage is reported as 0%, but the nested item properties do carry descriptions for weekday, start and end. The description adds genuine meaning the schema lacks: the empty-list-clears semantics and that times use the settings' time zone (the schema instead says 'the person's mock time zone'). No further detail on validation, overlap handling, or ordering of rules.

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 (replace) and resource (whole recurring weekly hosting schedule) plus the exact shape of the input (weekday rules), which cleanly separates it from buddy_mock_schedule_add_override, buddy_mock_schedule_get and buddy_mock_schedule_delete. An agent can pick this tool without opening any sibling 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?

Gives concrete when-to-use context (recurring weekly rules) and an important exclusion: dated overrides are kept and are not accepted here, which implicitly routes override work to the sibling add_override tool. It also explains the clearing case via an empty list, but never names the sibling alternative explicitly.

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