Open a result

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

Annotations already cover read-only/idempotent/non-destructive, yet the description adds genuinely new behavior: a missing id yields a not-found message rather than an error, and a LOCKED private note is refused so the person must open it themselves. Those refusal and failure modes are exactly the context annotations cannot express.

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 short sentences, front-loaded with the action and return shape, then usage, then edge cases. Every sentence carries distinct information; nothing is repeated.

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 no output schema, the description still specifies the return granularity (section vs. whole note), the not-found path, and the locked-note refusal. An agent has everything needed to call it and interpret the outcome.

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% and the single 'id' param is already documented as 'A result id from search_notes', so the description only restates that provenance. Baseline 3 is right for one fully documented parameter with no added syntax or format detail.

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?

Names a specific verb (open) and resource (one result from search_notes) and states what comes back: the full section, or the whole note if short. That return-behavior contrast with search_notes' snippets makes it instantly distinguishable from the sibling.

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 sequencing ('Use it after search_notes, when a snippet is not enough to answer') gives both the prerequisite and the trigger condition, and it names the alternative (search_notes) by implication. It also tells the agent what to do on a stale id: search again.

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