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

Even with readOnlyHint, idempotentHint, and openWorldHint already provided, the description adds substantial behavioral context: empty results mean the exact combination has no entry, not that the condition is non-presumptive; the legal authority repeats in a provenance block on every row; a date can be null for grouped rows; and a condition description naming a qualifying circumstance is a limit, not a detail. It also discloses that the tool does not read service records, managing expectations for end-to-end eligibility determination.

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 long but every sentence carries critical information: the query trigger, return contents, filter constraints, empty-result semantics, and a limitation. It front-loads the core purpose and use case, then layers necessary caveats. There is no filler or redundant restatement of the title or schema.

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 tool with three optional parameters locked down by the schema and rich annotations, the description is complete: it covers purpose, filter mechanics, required input, empty-result interpretation, provenance/date behavior, and a key limitation about service records. Nothing needed to select and invoke the tool correctly is 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?

Schema coverage is 100%, so the schema already documents condition, serviceEra, and exposureType. The description goes beyond the schema by explaining that at least one is required, that they combine with AND as a narrowing intersection, and that each filter is refused unless it contains a word of three or more characters. This adds meaningful semantic constraints beyond the property descriptions.

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 verb ('check') and resource ('presumptive eligibility') and precisely defines the queries it answers: whether a condition is presumptively service connected, or which conditions are presumptive for an exposure or era. It clearly distinguishes itself from sibling rating and claims tools by focusing on presumptive service connection.

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 description explicitly says to use this tool 'when a veteran asks whether a condition is presumptively service connected, or which conditions are presumptive for a given exposure or service era.' It also gives important usage constraints: at least one filter is required, filters combine with AND, and every filter needs a word of three or more characters. It does not explicitly name alternatives or state when not to use the tool, so it falls short of a 5.

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