Update plan block

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

The description adds behavioral details not in annotations: returns the updated block and emphasizes partial updates ('Pass only the fields you want to change'). It also notes the title syntax for linking board tasks. Annotations already declare non-read-only and non-destructive; there is no contradiction. However, it doesn't cover potential error conditions or other side effects, keeping it just short of a 5.

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 concise with four short sentences, front-loaded with the main purpose. However, the title reference duplicates schema information and could be omitted, but overall it's efficiently sized and structured.

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 mutating tool with 7 params and no output schema, the description covers the core purpose, partial-update behavior, and return value. The schema provides exhaustive param details, so the description only needs to connect these elements. It succeeds but leaves out any note on when to use alternatives (covered under usage) and potential constraints like recurrence-dependent fields (covered in schema). Overall, adequate for this complexity.

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 describes all 7 parameters with 100% coverage, so the description adds limited value. The only param-specific mention is the title's `@boardSlug/N` reference, which duplicates the schema text. The general guidance 'Pass only the fields you want to change' applies across all params but offers no new parameter semantics. 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?

The description begins with 'Update fields of an existing day-planner block,' providing a specific verb and resource. It clearly differentiates from sibling tools like create_daily_plan_block and delete_daily_plan_block by emphasizing 'existing' and 'update.' The mention of partial updates and title linking further defines scope.

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 implies its use case: updating existing blocks, and instructs to 'Pass only the fields you want to change,' giving clear context for usage. It doesn't explicitly name alternatives or exclusions, but the phrase 'existing day-planner block' delineates from create/delete. Lacks explicit when-not-to-use.

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