Create plan block

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

Annotations already establish that this is a write operation (readOnlyHint=false) and non-idempotent. The description adds behavioral context beyond that: the `@boardSlug/N` syntax makes the title render as a clickable link, and it states that the tool returns the created block. There is no contradiction with 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?

The description is only three sentences, each carrying meaningful content: the core creation purpose, the linking feature, and the return value. It is front-loaded and free of filler. Every sentence earns its place.

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 that the tool has 6 parameters and no output schema, the description adequately covers the core purpose and the most notable special behavior (@boardSlug/N linking). It explicitly states that the created block is returned, which is helpful in the absence of an output schema. The remaining details, such as default recurrence, are left to the schema, which is well-documented.

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 input schema has 100% coverage with descriptions for all six parameters, so the baseline is 3. The tool description repeats the `@boardSlug/N` syntax already present in the title parameter description, but adds no new semantic detail for other parameters like `scheduled_time` or `recurrence`. Thus, it does not significantly elevate understanding beyond the schema.

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 uses a specific verb and resource: 'Create a block in the user's personal day-planner'. It explicitly distinguishes this from a 'board task', which immediately differentiates it from the many task/board sibling tools. The added detail about linking a board task via `@boardSlug/N` further clarifies its unique function.

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 gives clear context by stating that the block belongs to the user's own time-blocking schedule and explicitly says 'not a board task', which steers away from using this tool for board tasks. It does not name a specific alternative tool like 'create_task', but the exclusion is explicit enough. Overall, usage context is clear and unambiguous.

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