update_time_block

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

With no annotations, the description carries the full burden and does well: it discloses partial-update semantics ('Only the fields you pass change'), the required blocks:write scope, and the special PYUNTO_TM_PASSWORD + project_id requirement for encrypting memos on end-to-end-encrypted projects. It omits reversibility and result behavior, but the authorization and mutation semantics are unusually well covered.

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?

Four tight sentences, front-loaded with the mutation scope before the prerequisites. Every sentence carries operational weight, though the memo/encryption sentence is dense enough that it could be split for readability.

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 7-parameter mutation tool with no annotations and no output schema, the description covers identity lookup, partial-update behavior, scope, and the encryption prerequisite. Return-value details are absent but the tool has no output schema, and reversibility guidance is the only notable omission.

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 already 100% (baseline 3), and the description adds meaning beyond it by explaining where block_id comes from and why project_id must accompany a memo (so the memo is encrypted under the right key). That cross-parameter dependency is genuine added value.

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 ('Change') and resource ('an already-recorded time block') and enumerates exactly which fields are mutable (date, start/end, memo, task attribution). This clearly distinguishes it from siblings like log_time (create), delete_time_block, and list_time_blocks without needing to name them.

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?

Gives concrete context: obtain block_id from list_time_blocks, and confirm the current vs. intended state with the user before calling. It stops short of stating when not to use this tool (e.g., versus log_time for new entries), so it is strong but not exhaustive.

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