Search History

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

Annotations only cover the read-only/idempotent safety profile; the description adds genuinely useful behavior the schema cannot convey — the environment-variable gate, the ok:false failure mode with remediation instructions, and the AND-matching semantics. This is exactly the kind of auth/prerequisite disclosure that earns top marks.

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 dense sentences, front-loaded with what is searched and what is returned, then the critical gating caveat, then the matching rule. No filler and nothing repeated from the schema.

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 does carry return-shape information (visit counts, last visit time, ordering) and the disabled-path response. It stops short of describing pagination or how the time window interacts with limit, but nothing essential to a correct call is 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 the baseline is 3, but the description adds non-obvious semantics beyond the schema: every word in the query must match (AND, not OR), and results are ordered newest first. No syntax details for the time window (since_days/until_days) are added beyond the schema.

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+resource (search Arc's browsing history) and scopes it precisely by saying it matches text in the title or url and returns pages with visit counts and last visit time, newest first. It never names a sibling such as search_archive, so the boundary between 'history' and 'archive' is left to inference, which keeps it short of a 5.

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?

Gives clear operational context: the tool is OFF unless the server was started with ARC_MCP_ALLOW_HISTORY=1, and explains what happens when it is disabled. It also states the matching rule ('Every word in query must match'), but offers no guidance on when to prefer this over the sibling search_archive.

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