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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=false, openWorldHint=true; the description adds the meaningful behavioral detail annotations cannot: the default resolution of the visible flag (account setting) and the fact that assignments are a separate call. It does not address the non-idempotent/destructive profile (e.g. duplicate shifts if retried), which would be the remaining valuable addition.

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 with the operation class and the core action front-loaded, then the conditional parameter rule, then the follow-up call. No sentence is filler; even "POST /shifts" is a one-token endpoint anchor.

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?

Adequate for an 8-parameter mutation tool: required inputs, the conditional flag, and the next-step workflow are covered, and time formats are handled by the schema. With no output schema, one gap remains — the description never says what comes back (presumably a shift id) that the subsequent assign call needs.

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 the baseline is 3, but the description adds semantics the schema lacks: the default behavior of visible and the intent behind setting it. It also frames number_of_employees as a planning headcount rather than an assignment, which prevents a misread of the required parameters.

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?

Opens with an explicit operation class ("WRITE"), a specific verb+resource ("plan a new shift"), and states the scope (location, working area, headcount). It also names the sibling used for the follow-up step, so the agent can distinguish it from papershift_assign_user_to_shift and the list/get siblings without opening the 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 guidance for the one ambiguous parameter ("Set visible to true only if employees should see it right away") and routes the agent to papershift_assign_user_to_shift for staffing. It stops short of stating prerequisites (e.g. that location_id/working_area_id must exist, or how to obtain them), so usage is clear but not fully bounded.

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