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

With no annotations, the description carries the full burden, and it delivers notable behavioral context: notes accumulate as a 'patina of passage' and render on the piece page and in read()/dig(), i.e. persistence and visibility. It omits auth requirements, rate limits, and whether notes are editable/deletable, so a small gap remains.

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?

Front-loaded with the core action, then backgrounded with differentiation and constraints; sentences earn their place. Slightly dense with em-dash asides, but no filler.

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?

No output schema exists, and the description compensates by stating where notes surface (piece page, read()/dig()). Combined with the clear purpose and usage guidance, an agent has what it needs, though the absence of any permission/limits note slightly narrows completeness.

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 four parameters including the kind enum-ish set and the ~400-char note limit. The description adds tonal/length meaning ('one breath, a line or few', 'not a caption, not a summary') but this largely echoes the schema, so baseline 3 applies.

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 and resource ('leave a small decorative trace in a piece's margin') and immediately distinguishes it from the sibling mark_piece, with the conceptual difference spelled out ('marks steer foragers off covered ground; a note leaves resonance'). An agent can differentiate this from mark_piece without opening either schema.

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?

Explicit when/when-not: names the alternative (mark_piece) and the condition that selects each, plus concrete content exclusions ('Do NOT explain, summarize, or analyze the piece — say the thing beside the thing') and a length constraint ('one breath, a line or few').

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