calendar.entities.update

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

The description discloses key behavioral traits: it is 'SIDE-EFFECTFUL' (a warning), idempotent per patch, and returns `{entity}`. It also explains the soft-retire behavior (set `active` to false without losing history). Since no annotations are provided, the description carries the full burden, and it does so well by flagging side effects and idempotency. It could mention whether patches are partial (only provided fields updated) but the schema implies that.

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 and front-loaded: it starts with the side-effect warning, then the action, then the key behavioral details (idempotency, return value), and finally the alternative. Every sentence earns its place, and it's compact enough for an agent to parse quickly.

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 the tool's complexity (6 params, 1 required, no output schema), the description covers the essential behavioral aspects: side effects, idempotency, return shape, and the soft-retire distinction. It doesn't explain the return format in detail (e.g., what fields `{entity}` contains), but that's likely inferable from the entity context. The lack of an output schema is partially compensated by the `{entity}` return mention. A 4 is fair because it's complete for an agent to call it correctly, though a bit more detail on partial patch semantics would push it to 5.

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 the schema already documents all 6 parameters. The description adds value by explaining the `active` field's soft-retire semantics, which is not fully captured in the schema ('Set false to soft-retire the entity without losing history' appears in both, but the description emphasizes it). However, the description doesn't add much beyond the schema for other parameters, so a 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 clearly states the tool's purpose: 'Patch an existing entity's fields' with a specific verb ('Patch') and resource ('existing entity's fields'). It also distinguishes itself from the sibling `calendar.entities.delete` by explicitly noting the difference between soft-retire and hard delete. The mention of `active` field and soft-retirement adds specificity.

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 clear context for when to use this tool: to update an entity's fields, including soft-retiring via `active: false`. It explicitly contrasts with `calendar.entities.delete` for hard delete, which serves as an alternative. However, it doesn't explicitly state when NOT to use it (e.g., for creating entities, which is `calendar.entities.add`), though the sibling list makes that inferable.

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