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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), so the description's main added value is naming the returned fields (dutyMode, onDutyTime, tier) and the exact endpoint. With no output schema present, that return-shape detail is genuinely useful, though nothing is said about pagination or access scoping beyond the schema's own default note.

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?

One compact sentence front-loads the core behavior, followed by a short parenthetical of returned fields and the raw endpoint path. The endpoint is marginally redundant but the whole thing is short and earns its place.

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 simple two-parameter read tool with full schema coverage and annotations covering safety, the description supplies enough: what it returns and the fields involved. Only the absence of fallback/error behavior and any hint of response structure beyond field names keeps it from a 5.

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 both user_id and team_ids are already fully documented, including how to obtain GUIDs. The description adds no syntax, format, or edge-case guidance beyond the schema, 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-and-resource combination: retrieving whether a user is on or off duty per team, plus the underlying endpoint. Clear enough that an agent understands the operation, but it never distinguishes itself from close siblings like signl4_get_duty_summary or signl4_list_duty_schedules.

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?

There is no statement of when to use this versus signl4_get_duty_summary or signl4_list_duty_schedules, nor any prerequisite context. Usage is only implied by the resource name, leaving the agent to guess which duty-related tool applies.

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