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

Adds real behavioral context beyond annotations: it requires an Authorization Bearer token (trial or contribution key) and consumes one available read per call, which explains why readOnlyHint=false despite the 'read' verb. The note that budgets/token estimates are approximate costs, not billing, is useful non-obvious context.

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?

Four short, dense sentences with no padding, and the core action plus its budget constraint are front-loaded. Slightly telegraphic, but every sentence carries information.

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?

Covers auth, quota, pagination, and budget semantics well for a quota-consuming read tool with no output schema, but the low parameter coverage leaves key inputs (id, q, searchId) meaningfully unexplained.

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 only 20% (just searchId), so the description must compensate. It loosely covers cursor ('nextCursor requests another excerpt') and maxChars (the 'budget'), but leaves q, id, and searchId unexplained, and even renames cursor to 'nextCursor', which could confuse an agent.

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 ('Read') and resource ('selected evidence') plus a scoping constraint ('within a JSON character budget'). This distinguishes it from the sibling search_research, though it doesn't explicitly name that alternative.

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?

Provides operational context (auth required, consumes one read, cursor fetches another excerpt) but never states when to use this vs search_research or the other siblings. Usage is implied through the pagination and quota notes rather than spelled out.

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