Exa Ultra mode

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

With no annotations to lean on, the description carries the full burden and does so: it discloses the configuration is global ('applies to every agent and session on this machine'), quantifies latency and dollar cost per mode, and names the EXA_AGENT_MAX_COST cap (default $1/run) that bounds the max tier. That is exactly the blast-radius context an agent needs before mutating shared state.

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-loaded with the verb and resource, then the mode tiers, then the global-scope warning and the usage restriction. The cost/latency figures are dense but each is decision-relevant; the tier list reads as a single run-on block rather than scannable lines.

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-param, zero-required configuration tool with no output schema, everything needed to call it safely is present: what the modes buy, what the setting affects globally, and when not to touch it. Return shape for the show case is the only minor omission and is inferable from the 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 coverage is 100%, so baseline is 3; the description exceeds it by unpacking each enum value into concrete latency, cost, and downstream effect (lite vs auto vs deep-reasoning search, agent effort minimal/low/ultra). The reset parameter is left entirely to the schema, which keeps this short of a 5.

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 pair of verbs and a precise resource: show or set the server-wide default quality mode applied when a call omits type/effort. None of the exa_* siblings touch server configuration, so an agent can place it immediately 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?

Explicit scoping on both sides: the mode only takes effect when a call sets no type/effort, and the description closes with the constraint 'Only set it when the user asks'. Omission-as-read is spelled out in the schema, so both the when and the when-not are covered.

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