Verify an instance path resolves

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

Annotations already carry readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds real context beyond that: it declares it reads no properties, reports cost=medium, states prerequisites (active-client, resolved-target), and describes the return shape including the omitted-field behavior. Return format is well disclosed, so 4 is warranted.

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?

Front-loaded with purpose, then usage, then return shape, then a compact metadata tail. Every sentence carries information, though the trailing structured block (phase/cost/idempotency/requires/produces/safety) is somewhat dense and partly overlaps annotations.

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?

No output schema exists, yet the description fully specifies the return object and its optional-field behavior, plus prerequisites, cost, and failure guidance pointing to tool-schema. For a simple two-parameter read tool, 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 coverage is 100%, so both parameters are already documented in the schema, including the dotted-path resolution semantics. The description restates the signature and echoes the path concept without adding syntax or format detail beyond the schema. Baseline 3 applies.

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 (check/verify) and resource (a dotted instance path resolving to a real Instance), and immediately scopes it with 'without reading any properties'. This distinguishes it cleanly from property-reading siblings without needing to open their 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?

Explicitly names the condition for use ('pre-flight check before click-button / type-text-box / get-instance-properties') and the payoff ('fail fast with a clear message instead of acting on a stale or wrong path'), with the concrete rationale that UI is created/destroyed dynamically. Naming specific sibling tools leaves little to inference.

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