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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds useful behavioral context by stating the output is a 'concise text answer' and that it covers 'open or completed' item statuses. It does not go deep into pagination or response details, but with annotations covering safety, this is sufficient.

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?

The description is a single, highly informative sentence that front-loads the main action and includes a conditional usage note. Every clause earns its place, with no wasted words.

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?

Given the tool's simplicity, the presence of a full output schema, and annotations guaranteeing safety, the description is mostly complete. It covers the core use case and exclusions, but does not explicitly mention how to set filters like due_before or item_status, which are left to the schema. Still, this is adequate for a list 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?

Schema description coverage is 100%, and the parameter descriptions in the schema fully document each parameter. The tool description adds no additional parameter semantics, so the baseline score of 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?

The description clearly states the tool lists open or completed TODO/action items as a concise text answer, with a specific verb and resource. It also distinguishes itself from the visual TODO workspace, making its scope unambiguous.

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 explicitly says when to use the tool ('when the user asks how many tasks, follow-ups, or saved action items are currently pending or completed') and explicitly states what not to use it for ('do not use it to open, browse, filter, or manage the visual TODO workspace'). However, it does not name alternative tools, leaving a slight gap.

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