append_periodic_note

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

No annotations are provided, so the description carries the full burden. It usefully discloses that existing frontmatter is preserved exactly, and that a template-based creation happens when createIfMissing is true. This goes beyond schema. It doesn't cover failure modes (e.g., hash_conflict implications) or non-template creation behavior, but covers the key mutation semantics well.

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?

Three tight sentences, front-loaded with the core action and period types, then the two most important behaviors (frontmatter preservation, create-if-missing). Zero filler, every clause earns its place.

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?

With 5 params, no output schema, and no annotations, the description does a solid job covering the mutation semantics and creation behavior. The main gap is not describing what happens on hash_conflict failure or what is returned, but those are partially mitigated by a well-described schema (prevHash explanation) and the append operation's obvious return shape.

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 documents all five parameters. The description adds marginal value by noting frontmatter preservation and template-based creation, which relates to createIfMissing. The prevHash guard is described in the schema; the description doesn't add beyond it. Baseline 3 is appropriate given full schema coverage.

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?

Uses a specific verb+resource ('append text to a periodic note'), enumerates the supported period types (daily through yearly), and distinguishes from the sibling, generic append_note, by the period-scoping. Clear and immediately actionable.

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 when to use it (periodic/dated notes) via the period enums, and its name contrasts with generic append_note for regular notes. However, it doesn't explicitly name an alternative or state when NOT to use it, leaving differentiation to inference rather than stating it outright.

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