List custom watchlists by exact ID with counts and duplicate-name diagnostics. Does not choose a list by name.
List custom watchlists by exact ID with counts and duplicate-name diagnostics. Does not choose a list by name.
| Name | Required | Description | Default |
|---|---|---|---|
| target_id | No | Exact Chrome tab target ID from browser_list_tabs. Required for changes. | |
| expected_layout_id | No | Expected saved-layout ID. A mismatch stops the operation before writing. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds return-content context (counts and duplicate-name diagnostics), which is genuinely useful, but says nothing about pagination, ordering, or whether duplicate names affect which lists are returned.
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 short sentences, front-loaded with the verb and resource, with the scoping constraint immediately after. Zero 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?
For a read-only list tool with full schema coverage and safety annotations, the description covers what it returns (counts, duplicate-name diagnostics) and what it will not do (resolve by name). Only secondary details like ordering or result-size limits are missing.
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 both parameters are documented in the schema; baseline 3 applies. The description's "by exact ID" phrasing adds no parameter meaning, and it is ambiguous which ID is meant since the schema's target_id is a Chrome tab target ID rather than a watchlist identifier.
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?
"List custom watchlists" gives a specific verb and resource, and the addition of "by exact ID" plus "Does not choose a list by name" scopes it clearly. It stops short of naming the sibling it is being distinguished from (watchlist_get / watchlist_get_active), so the differentiation is inferred rather than explicit.
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 exclusion "Does not choose a list by name" implies you use this for enumeration/validation rather than resolution, but no alternative tool is named and no condition (e.g. "use watchlist_get when you already have the ID") is stated. Usage is implied, not spelled out.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.