web_notes

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

Annotations only tell us it is a write-capable, non-open-world tool; the description supplies the key behavioral facts they omit — persistence across sessions, path-like key grouping, and prefix-based listing. It does not disclose whether set overwrites, note scope (global vs per-profile/site), or any TTL/size limits, which leaves real gaps for a stateful store.

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?

Two sentences, fully front-loaded: purpose first, then a concrete use-case list, then the key-format convention. No filler sentences.

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?

Covers all four actions, the persistence intent, and key structure for a 4-param, zero-required tool with no output schema. It does not describe return semantics for get/list (e.g. missing-key behavior or output shape), which the absence of an output schema would otherwise justify.

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%: value requirement for set, action meanings, and prefix semantics are all already documented in the schema. The description's path-like key example repeats the schema's own example rather than adding new meaning, so the 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 resource (a cross-session value store) and enumerates all four verbs (set/get/list/delete) explicitly. No sibling tool (browser_*, web_crawl, web_search, etc.) does persistent storage, so it is easily distinguished without opening the 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?

'Use for state needed in a later session' gives a clear triggering condition, and the examples (last id seen, learned URL pattern, checkpoint) pin down the intended context. It does not name when NOT to use it or any alternative, so it stops short of a 5.

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