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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds real value beyond them by explaining the calendar's semantics — that durations in days are measured in working days and that scheduling/workload consume this data — which an agent cannot infer from annotations.

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 dense sentence that front-loads the resource and return contents, followed by the semantic note. Nearly every clause earns its place, though the userId phrasing is both wrong and verbose.

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?

With no output schema, the description must carry return-value explanation; it names the categories but not their shape or format (e.g., how hours-per-day and days-off are structured). The nonexistent userId parameter is left unresolved, creating a real ambiguity for a zero-argument tool.

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?

The input schema has zero properties, so the baseline would be 4. However, the description repeatedly references a 'userId' input ('public holidays (no userId)', 'with userId'), which does not exist in the schema — this actively misleads an agent into attempting to pass an argument the tool does not accept.

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 ('Read the workspace's working calendar') and enumerates exactly what it returns: working weekdays, hours per working day, and days off. This clearly separates it from siblings like add_day_off, remove_day_off, and get_workload.

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?

It gives domain context that implies when the result matters ('Task durations in days count working days only, and scheduling and workload use this calendar'), but never says explicitly when to call this tool or which alternative to pick. No prerequisites or exclusions are stated.

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