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

Annotations already cover read-only, idempotent, open-world, and non-destructive behavior. The description adds meaningful context beyond those: it returns live-only flags, emphasizes this is a LIVE snapshot rather than the deduplicated record, and discloses a concrete cost of 10 Zooq credits. No contradiction with annotations.

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: purpose and distinction, return payload highlights, and cost. The most decision-relevant information is front-loaded in the first sentence.

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 two-parameter, read-only tool with a rich output schema, the description covers purpose, scope, exclusions, downstream usage, key return value, and cost. It is sufficiently complete for an agent to select and invoke the tool correctly.

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%, and the schema already explains that handle OR entityId can be provided and that entityId wins when both are present. The description only reiterates 'by handle or entityId' without adding parameter-level detail, so the baseline of 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 ('snapshot'), resource ('one profile'), and input mechanism ('by handle or entityId'), and immediately distinguishes itself from the deduplicated records returned by other profile/* endpoints. Also lists live-only flags and the key output entityId, which differentiates it from siblings like profile_full or profile_entity_id.

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 says this is NOT the deduplicated dataset record other profile/* endpoints return, giving a clear when-not signal. It also explains that the returned entityId is required by every other live person endpoint, implying this tool is the right entry point when you need live data or a downstream entityId.

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