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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior. The description adds genuinely new behavioral context: results carry no page text by default, billing is a flat $0.08, measured latency is 1.4 seconds, and `id` is the URL to pass to post_exa_contents. No contradiction with annotations.

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 dense but well-organized: the semantic-search purpose comes first, followed by return shape, operational facts, and sibling routing. It is longer than minimal, but every sentence carries operationally useful information, including cost, latency, and downstream usage.

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 an 11-parameter search tool with a rich schema, output schema, and comprehensive annotations, the description covers behavior, return-value semantics, sibling selection, and operational constraints. Nothing material is missing for an agent to invoke it correctly or route to an alternative.

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 input schema already documents all 11 parameters in detail. The description adds a helpful summary of the required `query` and the main narrowing parameters, but it introduces no meaning beyond what the schema already provides, so the baseline of 3 is appropriate.

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 ('Search') and resource ('the web'), then immediately clarifies the distinguishing approach ('by meaning rather than by keyword'). It also names sibling alternatives and differentiates itself from them, so an agent can tell it apart without inspecting other schemas.

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?

Explicitly states when to choose this tool over post_tavily_search (when the query is a description rather than keywords), and gives routing conditions for Tavily (want text in same call) and post_exa_answer (want a written answer). This is concrete, actionable guidance with named alternatives.

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