clear_cache

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

Adds substantial context beyond the annotations: it discloses exactly what is removed (cached answers, session cookie, back-off state) and, crucially, what is preserved ('Saved Trending Now history and the watchlist are never touched'). This confirms and enriches the destructiveHint=false / idempotentHint=true profile rather than contradicting it.

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?

Front-loads the core action and the rejection/safety caveat is well placed at the end. The 'what' enumeration line is dense but each token maps to a real option, so little is wasted.

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 two-parameter cache-clearing tool with an output schema, the description covers destruction scope, parameter values, and side effects. An agent has everything needed to invoke it correctly; return values are handled by the output schema.

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 0%, so the description carries the full burden and does so: it defines the default value of 'what' ('expired — only answers too old to be used even as a fallback'), lists the alternative scopes (all, trending, timeseries, regions, related, explore), and explains reset_session's side effects. Both parameters are fully specified in prose.

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 and resource ('Delete saved answers') and even the downstream effect ('so the next call asks Google again'). No sibling tool clears cache, so the agent can place it immediately among the trending/history tools.

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 context for use: 'reset_session' is 'for a clean start after a block', and the 'what' values enumerate the scopes. It stops short of an explicit when-to-use-this-vs-alternatives statement, but no competing cache tool exists.

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