cache

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

Annotations only provide readOnlyHint=false, so the description carries the burden of disclosing mutating behavior; it does by saying 'clear to delete rows.' It also adds useful context about locality, latency, and full-text search behavior (Chinese substrings and English words), though it does not detail destructive edge cases or return behavior in depth.

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?

The description is three tightly written sentences with no filler. It front-loads the core resource and action, then delivers performance guidance and mode routing in a logical progression.

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 9-parameter, zero-required tool with no output schema, the description supplies the essential decision-making context: what data is cached, when to prefer it, and how to invoke each major mode. The remaining parameters (url, since_hours, limit, kind) are fully described in the schema, so nothing needed for correct invocation 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 coverage is 100%, so the baseline is 3, but the description adds real semantics by mapping query/get/stats/clear to their intended uses and by noting a capability constraint ('works for Chinese substrings and English words'). This goes beyond what the parameter descriptions already state.

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?

The description opens with a specific verb and resource: 'Query the LOCAL CACHE of every page this server has fetched and every search it has run.' It clearly defines the tool's scope and differentiates it from re-fetching or re-searching, making its purpose unambiguous.

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?

It explicitly says 'Check here BEFORE re-fetching or re-searching' and quantifies the trade-off ('a hit is instant and free while a fresh fetch costs 5-60s'). This gives an agent a concrete rule for when to use the cache instead of the sibling fetch/search tools, and it also routes to the correct subcommand (query/get/stats/clear).

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