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

Annotations only declare readOnly/openWorld/destructive; the description adds material context they cannot: the byte budget, truncation behavior, authentication requirement, a shared 60-call bucket with source_metadata refilling at 1/sec, independence from daily/company limits, and that results contain no data rows. It also warns that snapshot readiness is independent of legal eligibility, which prevents a real misinterpretation.

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 the output contract before operational constraints and routing, with zero filler sentences. The telegraphic clause stacking (rights, exclusions, attribution, clocks, coverage) is dense but readable.

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?

Even with an output schema present, it calls out the summary keys datasets_total and truncated so the agent knows truncation is observable. Given one optional parameter and a read-only, rate-limited tool, nothing needed 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 the baseline is 3; the description earns extra by enumerating what the full-detail branch actually yields (rights, exclusions, attribution, clocks, coverage) rather than repeating the schema's 'full detail' wording. It stops short of describing the shape of those fields.

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 and resource plus exactly what is returned (IDs, English names, per-surface status, licences) and the 8000-byte bound. It explicitly separates itself from source_metadata and get_company, so an agent can pick it without opening a schema.

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?

Gives the selection rule for the single parameter ('Pass dataset_id for full rights...'), names two sibling alternatives with the condition that selects each, and adds a hard exclusion ('Do not look up natural persons'). Nothing is left to inference.

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