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

Annotations already declare idempotentHint=true and destructiveHint=false, and the description adds real merge semantics: only passed days change, omitted days keep current hours, and an omitted timezone keeps the current one. It does not disclose permission requirements for editing a team's schedule versus your own.

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, front-loaded with the mutation and immediately followed by the identification and partial-update rules. No filler or restatement of the tool 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?

No output schema is needed for a setter, and the annotations cover the safety profile, so the remaining burden is minimal. The description covers entity resolution, partial updates, and timezone defaulting, leaving only error behavior for invalid ids/timezones unstated.

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, but the description adds provenance not present in the schema: where team ids come from (get_settings with no arguments) and the self-schedule case for entity=user. The timezone parameter's 'optionally the timezone they are read in' phrasing also clarifies its role beyond the schema text.

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 ('Change the weekly hours') plus the two entity types it applies to (team calling hours vs rep availability) and the timezone side effect. It does not name or differentiate against the sibling set_user_availability, which appears to overlap for the 'user' branch, so sibling differentiation is incomplete.

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 identification guidance: team by team id sourced from 'get_settings with no arguments', rep by user id, and self-schedule when entity=user with no id. It also states the partial-update rule ('Only the days you pass change'). It stops short of saying when to prefer this over set_user_availability.

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