List overdue plan blocks

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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds the filtering behavior (due before date and not done) but does not disclose additional traits such as ordering, pagination, or response format. This adds some value beyond annotations but is not rich behavioral context.

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 that states the action and key filters with no redundant words. Every element contributes to understanding the tool's purpose.

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, filtered list tool with one well-documented parameter and good annotations, the description is complete. It conveys the exact selection criteria and scope ('the user's'), and no output schema is expected for a simple list operation. No critical gaps.

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 coverage is 100%: the single parameter local_date has a clear description ('Local date YYYY-MM-DD — blocks overdue relative to this date'). The main description echoes this with 'due before the given local date' but does not add semantics beyond schema. Baseline 3 is appropriate.

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?

Description uses a specific verb ('List') and precisely identifies the resource ('the user's day-planner blocks') with clear qualifiers ('due before the given local date and are still not done'). This distinguishes it from the more general sibling tool list_daily_plan_blocks, which presumably lists all blocks.

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?

The description clearly implies its use case: retrieving overdue, incomplete day-planner blocks. However, it does not explicitly mention alternatives or exclusions (e.g., 'use list_daily_plan_blocks to see all blocks'), so it lacks the explicit 'when not to use' guidance that would earn a 5.

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