Get Field Schema

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful context: it's a lightweight subtree fetch versus a large schema, and it accepts find_field output paths directly. This is meaningful but not rich — no mention of failure modes, pagination, or edge cases, which the annotations don't require given the read-only nature.

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?

Three sentences, each earning its place: core purpose, usage guidance with sibling differentiation, and input-compatibility note. Front-loaded with the primary function and zero filler.

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?

Complete for a read-only tool with a defined output schema (so return values need no explanation), 100% parameter coverage, and annotations that establish the behavioral profile. Purpose, when-to-use, and input compatibility are all addressed — nothing an agent needs to call it 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 description coverage is 100%, so both slug and field_path are fully documented with examples in the schema. The description adds one genuinely useful note — 'Paths from find_field output work directly' — which clarifies the expected format of field_path beyond the schema. This is a real but marginal addition over the schema's baseline.

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 (drill into/get) and resource (a field's schema within an endpoint), and the second sentence explicitly contrasts it with fetching the full 70KB endpoint schema — which differentiates it from the sibling get_endpoint. An agent can tell it apart from its siblings without opening 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?

The 'Instead of fetching the full 70KB endpoint schema, use this to get just the subtree you need' line gives clear context for when to choose this tool over a full-schema fetch. It also notes compatibility with find_field output. However, it doesn't name alternatives explicitly (e.g., get_endpoint) or state when not to use it beyond the size heuristic.

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