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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description contributes only scope information (upcoming assignments, active projects) and says nothing about time window, freshness, or volume of results, which is the remaining behavioral gap.

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?

A single front-loaded sentence with no filler. The parenthetical '(who works where and when)' is a useful gloss on 'assignments' rather than padding, though the fragment style lacks a clear subject-verb frame.

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 and no parameters, the description is the sole source of return-value information, and it only sketches the contents. 'Upcoming' has no defined horizon and 'active projects' is undefined, so an agent cannot predict result shape or size before calling.

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 tool takes no parameters, so there is nothing for the description to disambiguate. Baseline 4 applies for a zero-parameter tool.

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?

Names the resource (the planbook) and enumerates its contents: upcoming assignments with who/where/when, plus active projects. That is enough to know what the tool returns, but there is no verb and no explicit differentiation from siblings like fetchProjectsContext or fetchProjectBoard.

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?

No statement of when to call this versus the many sibling context fetchers. The agent must infer from the word 'planbook' and the sibling list that this is the scheduling/planning view rather than the project or task view.

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