update_block

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

With no annotations, the description must disclose behavioral traits. It does state that IAL metadata is preserved, which is a useful behavior, but it omits critical aspects like whether the update is destructive, whether it can partially fail, any permission requirements, or what happens to other block properties. The mention of preservation is also partially redundant with the preserve_ial parameter, so the added transparency value is limited.

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?

A single sentence that is concise, front-loaded with the action, and includes a meaningful qualifier. No wasted words, and it covers the core purpose effectively.

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 mutation tool with no annotations and no output schema, the description is minimal. It does not explain return values, error behavior, prerequisites (like whether the block_id must exist), or side effects. The presence of two optional boolean parameters (preserve_id, preserve_ial) is not elaborated, and the description does not mention how they affect the update. This leaves significant gaps for an agent to use the tool correctly.

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 coverage is 100%, with all four parameters described individually. The description adds no extra semantic value beyond the schema: 'new content' repeats the data parameter's description, and 'preserving IAL metadata' echoes the preserve_ial parameter. Baseline of 3 is appropriate since the schema already carries the parameter meaning.

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 action ('Update a SiYuan note block') and the resource ('note block'), with a specific qualifier about preserving IAL metadata. This is distinct from all sibling tools, which are read/search/generate operations, making the purpose immediately clear.

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 provides no guidance on when to use this tool versus alternatives, nor any exclusions or prerequisites. Sibling tools exist for reading blocks (get_block_kramdown) and searching (siyuan_search_blocks), but the description does not contrast with them or indicate the appropriate context for an update operation.

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