update_block

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states that the tool updates content but does not disclose that existing content is replaced, whether the block must already exist, or any side effects or permissions required. This is a significant gap for a mutation tool.

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 two concise sentences with no redundant wording. The core action is front-loaded in the first sentence, and the usage guidance is brief and direct.

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 two-parameter tool, the description covers the basic action and usage context. However, the absence of annotations and output schema means the description should ideally note replacement behavior or error conditions to be fully complete. It is adequate but has clear 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 description coverage is 100%, so each parameter (block_id and content) is already documented in the schema. The description adds the context of 'modify specific content' but does not provide additional parameter-level detail beyond what the schema offers, aligning with the baseline of 3.

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 states a specific verb ('Update') and resource ('an existing block's content'), clearly identifying the tool's function. It differentiates from sibling tools like update_page and append_blocks by focusing on modifying existing block content rather than page-level updates or adding new 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 phrase 'Use when user wants to modify specific content' provides an explicit trigger condition for when to invoke this tool. It gives clear context for usage, though it does not explicitly mention exclusions or compare against alternatives like append_blocks or delete_block.

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