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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds only the pre-regeneration workflow context; it says nothing about what the plan contains or how an absent plan is represented. A 3 reflects modest added value on top of the 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?

Three short sentences, zero filler, with the core action and default stated first and the usage rationale last. Every clause carries information.

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 an output schema, rich annotations, and a fully documented optional parameter, the definition covers what an agent needs to call it correctly. It could still say what a returned plan looks like or how an empty day behaves, but that is largely the output schema's job.

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 single 'date' parameter already documents the YYYY-MM-DD format, ISO datetime tolerance, and today default. The description merely repeats the default, adding no meaning beyond the schema, so the baseline of 3 applies.

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 user's plan') with a scope qualifier ('for a given day', 'Defaults to today'). The resource name 'plan' implicitly separates it from siblings like view_task and view_lists, but the description never names or contrasts an actual sibling.

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?

Provides a concrete use condition: 'Useful before regenerating so an agent can see what is already in place.' That clearly situates it ahead of save_plan in a workflow. It stops short of explicit when-not guidance or naming alternatives such as search_tasks.

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