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

Annotations already declare destructiveHint=true and idempotentHint=true, so the write/overwrite nature is covered structurally. The description adds genuinely non-structured context: the authorization model (self vs admin) and the PRO+ / resourceMgmt feature gate, both of which affect whether a call can succeed.

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, front-loaded with the action and followed by the permission constraint and feature gate. No filler and nothing buried.

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 mutation tool with full annotations and full schema coverage but no output schema, the description covers the essentials an agent needs: what changes, who may change it, and the plan requirement. It does not state what happens to previously stored capacity values or what a failure response looks like, leaving a minor 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%, with userId, weekStart (Monday, YYYY-MM-DD) and hoursAvail (0-168) all documented in the schema. The description adds no additional parameter semantics, so the baseline 3 applies.

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 (set) and resource (a user's available hours for a given week), which cleanly separates it from the read-side sibling get_capacity. An agent can tell immediately what state this tool mutates.

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 description supplies a concrete selection rule: self-update is allowed for one's own capacity, while updating others requires org-level admin access. It lacks an explicit 'when not to use' or a named alternative (e.g., use get_capacity to read), so it stops short of a 5.

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