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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds useful traits beyond those: 'Deterministic, evidence-bounded and signed' and the fixed cost '0.012 USDC.' This gives an agent expectations about repeatability and output guarantees without contradicting 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?

Two compact sentences, front-loaded with the core action, then cost and behavioral guarantees. No filler or redundant restatement of the tool name.

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?

An output schema exists, so return format is covered. However, the open input schema and lack of usage guidance mean an agent must infer what to pass and when this tool beats phion_search or phion_inference. Cost and determinism help, but input semantics and selection criteria are 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?

The schema defines no named parameters, so there is no parameter documentation to augment. The description's 'Search, synthesize and cite evidence' implies a query/topic input, but the open schema (additionalProperties: true) leaves exact keys unspecified; with zero declared parameters, the baseline is 4.

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 states a specific composite action: 'Search, synthesize and cite evidence in one call.' This clearly identifies the tool's function and differentiates it from single-purpose siblings like phion_search or phion_inference by emphasizing the combined workflow.

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?

The phrase 'in one call, minimizing residual agent work' implies use when an agent needs the full search-synthesize-cite pipeline, but it never explicitly names alternatives or states when not to use it. Siblings such as phion_search and phion_inference exist but are not referenced.

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