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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description still adds real value with the 100-item cap, the due-date ordering, connection-level visibility scoping, and the fields returned. The one gap is what happens beyond the 100 cap — no truncation or paging guidance.

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?

Two sentences, zero filler, with scope and ordering front-loaded before the alternative-tool routing. Every clause carries information an agent needs.

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 zero-parameter read tool with rich annotations and an output schema, the description covers scope, ordering, cap and differentiation adequately. The only missing piece is how to obtain results beyond the 100-item cap, which matters given the stated limit.

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 schema has zero parameters, so there is nothing to disambiguate; baseline 4 applies. The description correctly implies no filtering arguments exist, but does not call out that filtering must be done client-side.

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?

Specific verb + resource ('list open actions') plus scope ('visible to this connection'), ordering ('soonest due first') and returned fields (assignee, remit, source). It explicitly distinguishes itself from twelfth_list_projects, so an agent can route correctly without opening a 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 an explicit use case ('what is due or overdue') and names the alternative tool for the contrasting case ('for project-level progress use twelfth_list_projects'). Both the when and the when-not are stated.

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