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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely non-schema information: a per-call cost of $0.005 USDC settled via x402, which matters for an agent deciding whether to call it. It does not disclose limits such as max source size or how many calls the budget implies.

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 tight sentences: the mechanism and inputs first, the value proposition second, the cost last. No filler and nothing repeated from the schema verbatim.

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?

With no output schema, the description should carry more of the return-shape burden; 'with source markers' is a hint but not a description of the packed output. Inputs and pricing are covered adequately, but an agent cannot tell how passages are delimited or how the budget is enforced. Adequate but with clear gaps.

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 75%, so the schema already documents the pipe-separated url/text conventions and the default token_budget of 2000. The description restates the same concepts ('long texts or URLs', 'your question', 'token budget') without adding format or constraint detail. Baseline 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 and resource: it picks the passages most relevant to a question from long texts or URLs and packs them into a token budget with source markers. That is far more informative than the bare name 'context'. It does not, however, distinguish itself from adjacent siblings like chunk, summarize, rerank, or extract, so an agent must infer the boundary.

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?

'Fit more useful context into a prompt for less' implies the use case (preparing prompt context from long sources), which is useful but indirect. There is no explicit when-not guidance and no named alternative among the many compression/retrieval siblings. Usage is implied rather than stated.

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